©1995 by The American Society for Biochemistry and Molecular Biology, Inc.
Identification of the Ankyrin-binding Domain of the Mouse T-lymphoma Cell Inositol 1,4,5-Trisphosphate (IP) Receptor and Its Role in the Regulation of IP-mediated Internal Ca Release (*)

(Received for publication, November 2, 1994; and in revised form, December 27, 1994)

Lilly Y. W. Bourguignon (§) Hengtao Jin

From the Department of Cell Biology and Anatomy, University of Miami Medical School, Miami, Florida 33101

ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS AND DISCUSSION
FOOTNOTES
ACKNOWLEDGEMENTS
REFERENCES

ABSTRACT

In this study we have used several complementary techniques to explore the interaction between the membrane linker molecule, ankyrin, and the inositol 1,4,5-trisphosphate (IP(3)) receptor in mouse T-lymphoma cells. Using double immunolabeling and laser confocal microscopy, we have found that both cytoplasmic IP(3) receptor and ankyrin are preferentially accumulated within ligand-induced lymphocyte receptor-capped structures. The binding between ankyrin and IP(3) receptor appears to be very specific. Further analyses indicate that the amino acid sequence GGVGDVLRKPS in the IP(3) receptor shares a great deal of structural homology with the ankyrin-binding domain located in certain well characterized ankyrin-binding proteins such as the cell adhesion molecule, CD44. Biochemical studies using competition binding assays and a synthetic peptide identical to GGVGDVLRKPS (a sequence detected in rat brain IP(3) receptor (amino acids 2548-2558) and mouse brain IP(3) receptor (amino acids 2546-2556)) indicate that this 11-amino acid peptide binds specifically to ankyrin (but not fodrin or spectrin). Furthermore, this peptide competes effectively for ankyrin binding to IP(3) receptor-containing vesicles and/or purified IP(3) receptor, and it blocks ankyrin-induced inhibitory effects on IP(3) binding and IP(3)-mediated internal Ca release in mouse T-lymphoma cells. These findings suggest that this amino acid sequence, GGVGDVLRKPS, which is located close to the C terminus of the IP(3) receptor, resides on the cytoplasmic side (not the luminal side) of IP(3) receptor-containing vesicles. This unique region appears to be an important part of the IP(3) receptor ankyrin-binding domain and may play an important role in the regulation of IP(3) receptor-mediated internal Ca release during lymphocyte activation.


INTRODUCTION

Cytoskeletal proteins are known to be important participants in multiple functions involving cell regulation(1, 2) . Because the cytoskeletal network (e.g. microfilaments, microtubules, and intermediate filaments) can potentially form a physical link between the plasma membrane, organelle membranes, and nuclear membrane, it has been suggested that they are involved in transmitting important regulatory signals during cell activation by agonists(1, 2) . Specifically, Putney and his co-workers (3) have reported that IP(3)(^1)receptor-containing vesicles may be attached to the plasma membrane through cytoskeletal elements such as actin. In addition, our laboratory has found that both IP(3) binding and IP(3)-induced Ca release activities are significantly inhibited by cytochalasin D (an inhibitor for microfilament function) and colchicine (an agent known to disassemble microtubules)(4) . These findings support the notion that the cytoskeleton is involved in the regulation of IP(3) receptor-mediated function.

Recently, ankyrin (a cytoskeletal protein known to link membrane proteins such as erythrocyte band 3 (1) and lymphocyte GP85(CD44) (5, 6, 7, 8, 9, 10) to spectrin/fodrin-associated microfilaments) has been shown to bind IP(3) receptor in brain (11) and lymphoma cells(12) . Furthermore, the binding of ankyrin to its receptor displays inhibitory effects of IP(3) binding and IP(3)-mediated internal Ca release(12) . Consequently, certain cytoskeletal proteins (e.g. ankyrin) are strongly implicated in regulating internal Ca release(11, 12, 13) .

In this paper we have identified a unique 11-amino acid sequence, GGVGDVLRKPS, which is located close to the C terminus of the IP(3) receptor and appears to be an important part of the ankyrin-binding domain of the IP(3) receptor. The binding of ankyrin to this sequence is critically important for the regulation of IP(3)-mediated internal Ca release during lymphocyte activation.


MATERIALS AND METHODS

Cell Culture

The mouse T-lymphoma BW 5147 cell line (an AKR/J lymphoma line) was grown at 37° C in 5% CO(2), 95% air using Dulbecco's modified Eagle's medium supplemented with 10% heatinactivated horse serum (Life Technologies, Inc.), 1% penicillin, and 1% streptomycin.

Isolation of IP(3)Receptor-containing Vesicles (Light Density Vesicles)

The procedures for isolating IP(3) receptor-containing vesicles (light density vesicles collected from the 15-25% sucrose interface) were the same as those described previously(12) . These IP(3) receptor-containing vesicles were used for IP(3) binding assays, Ca flux measurement, and ankyrin binding as described below.

Double Immunofluorescence Staining

Mouse T-lymphoma cells were washed with Dulbecco's modified Eagle's medium and resuspended in the same medium. Ligands such as fluorescein-labeled concanavalin A (ConA) (50 µg/ml) or hamster anti-CD3 antibody (10 µg/ml) plus fluorescein-labeled rabbit anti-hamster IgG (50 µg/ml) were added directly to the cell suspension to induce patched or capped structures. Cells were then washed with 0.1 M phosphate buffer (pH 7.2) and fixed in 2% paraformaldehyde. Subsequently, cells were rendered permeable by 90% ethanol followed by staining with either rhodamine-conjugated monoclonal mouse anti-IP(3) receptor antibody (IPR.1) (12) or rhodamine-conjugated monoclonal mouse anti-ankyrin antibody (ANK016)(14) . In some cases, receptor-capped structures were induced by unlabeled ConA or unlabeled hamster anti-CD3 antibody. After capped structures were formed, cells were rendered permeable by 90% ethanol followed by staining with rhodamine-conjugated monoclonal mouse anti-IP(3) receptor antibody (IPR.1) and fluorescein-conjugated monoclonal mouse anti-ankyrin antibody (ANK016). To detect nonspecific antibody binding, cells were incubated with non-immune hamster or mouse serum followed by fluorescein-conjugated rabbit anti-hamster or rhodamine-conjugated goat anti-mouse IgG. No staining was observed in such control samples. Fluorescence-labeled samples were examined with a confocal laser scanning microscope (MultiProbe 2001 inverted CLSM system, Molecular Dynamics, Sunnyvale, CA).

Purification of IP(3)Receptor

Lymphoma light density vesicles collected from the 15-25% sucrose interface (according to the procedures described previously(12) ) were solubilized by adding Triton X-100 to a final concentration of 1% (v/v). Subsequently, the solubilized material was passed through a heparin-agarose column that was washed with 20 ml of buffer (50 mM Tris-HCl, pH 8.3, 1 mM EDTA, 1 mM beta-mercaptoethanol) plus 0.1% Triton X-100 and 0.25 M NaCl. The materials bound to the heparin-agarose were eluted with 3 ml of 50 mM Tris-HCl, pH 7.7, 1 mM beta-mercaptoethanol, 0.1% Triton X-100, and 0.5 M NaCl and then applied to an anti-IP(3) receptor (IPR.1)-conjugated affinity column. The IP(3) receptor was eluted from the column with a solution containing 0.05 M diethylamine, pH 11.0, 10 mM EDTA, and 0.05% Triton X-100. Purity of the IP(3) receptor preparations was confirmed by SDS-polyacrylamide gel electrophoresis, silver staining, and anti-IP(3) receptor antibodyspecific immunoblotting(12) . Purified IP(3) receptor was subsequently used for ankyrin binding assays as described below.

[^3H]IP(3)Binding Assay

Specific [^3H]IP(3) binding was determined by the method described by Guillemette et al. (15) . Aliquots of the light density vesicle fraction (i.e. materials from the interface of 15-25% sucrose layers) were incubated for 10 min at 4°C in 0.5 ml of a medium containing 25 mM Na(2)HPO(4), 100 mM KCl, 20 mM NaCl, 1 mM sodium EDTA, 1 mg/ml bovine serum albumin, and 0.05 µCi of [^3H]IP(3) (34.2 Ci/mmol, Amersham Corp.) at pH 7.4. In some cases, low density vesicles were pretreated with either ankyrin (10 µg/ml) alone or ankyrin (10 µg/ml) plus various concentrations (e.g. 1, 10, 50, and 100 nM and 1 µM, respectively) of the synthetic peptide (11 amino acids, GGVGDVLRKPS), followed by [^3H]IP(3) binding. Binding was estimated in the presence of various concentrations of unlabeled IP(3) ranging from 10 to 10M. The binding reaction was terminated by adding 2.5 ml of cold phosphate-buffered saline (pH 7.4) and filtrating through GF/B glass fiber filters that had been presoaked in phosphate-buffered saline containing 1% bovine serum albumin. The filter-associated radioactivity was analyzed by liquid scintillation counting.

Binding ofI-Labeled Ankyrin/Fodrin/Spectrin to 11-Amino Acid Synthetic Peptide and Scramble Peptide

Nitrocellulose discs (diameter, 1 cm) were coated with approx1 µg of either the 11-amino acid peptide (GGVGDVLRKPS) or a scramble peptide (GRDVKSPGLVG) at 4°C for 16 h. Following coating, the unoccupied sites on the discs were blocked by incubation with a solution containing 20 mM Tris-HCl, pH 7.4, and 0.3% bovine serum albumin at 4°C for 2 h. The discs were then incubated with various concentrations (20, 40, and 80 ng/ml) of I-labeled ankyrin/spectrin/fodrin (approx3000 cpm/ng) at 4°C for 2 h in 1 ml of binding buffer (20 mM Tris-HCl, pH 7.4, 150 mM NaCl, 0.2% bovine serum albumin). Following binding, the discs were washed three times in the binding buffer, and the disc-bound radioactivity was estimated. The nonspecific binding was determined in the presence of a 100-fold excess of respective unlabeled ligands and was subtracted from the total binding. Nonspecific binding was approximately 30% of the total binding. As controls, the ligands were also incubated with uncoated nitrocellulose discs to determine the binding observed due to the ``stickiness'' of various ligands. Nonspecific binding was observed in these controls.

Binding ofI-Labeled Proteins (e.g. IP(3)Receptor and CD44) or IP(3)Receptor-containing Vesicles (Low Density Vesicles) to Ankyrin

Radioactively labeled samples (e.g.I-labeled IP(3) receptor or I-labeled CD44 or I-labeled IP(3)-containing vesicles (approx1.5 times 10^4 cpm/ng)) were incubated with 30 µl of ankyrin conjugated to Sepharose beads (approx0.75 µg of protein) in 0.5 ml of the binding buffer. The binding was carried out in the presence or absence of various concentrations (1 nM-1 µM) of unlabeled competing 11-amino acid synthetic peptide (GGVGDVLRKPS) or the scramble peptide (GRDVKSPGLVG) at 4°C for 5 h under equilibrium conditions. Equilibrium conditions were determined by performing the time course (e.g. 1-10 h) of the binding studies. Following binding, the beads were washed in the binding buffer, and the bead-bound radioactivity was determined. Nonspecific binding was determined in the presence of either a 100-fold excess of unlabeled ankyrin or bovine serum albumin-conjugated Sepharose beads. The nonspecific binding was approximately 20-30% of the total binding and was subtracted from the total binding.

CaFlux Measurement in IP(3)Receptor-containing Vesicles (Low Density Vesicles)

Ca fluxes were studied in a reaction mixture containing 120 mM KCl, 20 mM Tris/HEPES, pH 7.2, 0.3 mM MgCl(2), 10 mM phosphocreatine/creatine kinase (10 units/ml) (Boehringer Mannheim), 3.75 µM ruthenium red, 1 mM Mg-ATP, and 0.5 mM EGTA. CaCl(2) was added to this solution to generate a range of free Ca concentration between 100 and 300 nM. Subsequently, Ca (5-10 µCi/ml or 50 Ci/µg; Amersham) and IP(3) receptor-containing vesicles (light density vesicles) (0.5 mg/ml) were added to the reaction mixture at 30°C for 25 min. In Ca release experiments, 20 nM IP(3) was added to these Ca-containing vesicles. The maximal amount of Ca release occurred 10 s after the addition of IP(3). In some cases, IP(3) receptor-containing vesicles (light density vesicles) were pretreated with either ankyrin (10 µg/ml) alone or ankyrin (10 µg/ml) plus various concentrations of the synthetic peptide (11 amino acids, GGVGDVLRKPS) (e.g. 1, 10, 50, and 100 nM and 1 µM, respectively) followed by the addition of 20 nM IP(3) to the reaction mixture for Ca flux measurements. The amount of Ca released from IP(3) receptor-containing vesicles (light density vesicles) was determined by a filtration method using Millipore filters (HAWP, 0.45 µm) and washing with a buffer containing 120 mM KCl and 20 mM Tris-HEPES, pH 7.2.


RESULTS AND DISCUSSION

Ankyrin is known to link various transmembrane proteins to the actin network through its interaction with spectrin or fodrin (a spectrin-like protein)(1, 2, 16) . For example, in erythrocytes ankyrin connects the band 3 anion exchange protein to spectrin(1, 16, 17) . In non-erythrocytes, ankyrin is associated with a number of physiologically important membrane proteins including the Na/K-ATPase(18, 19) , the voltage-dependent (20) , and the amiloride-sensitive Na+ channels(21) , as well as CD44(GP85)(5, 6, 7, 8, 9, 10) , possibly via its binding to fodrin.

Previously, we have shown that ankyrin interacts with the IP(3) receptor in mouse T-lymphoma cells(12) . In this study, using double immunofluorescence staining and laser confocal microscopic analyses, we have found that ligands such as anti-CD3 antibody and ConA induce an accumulation of the IP(3) receptor (Fig. 1, B and D) underneath receptor cap structures (Fig. 1, A and C). These results are consistent with previous findings indicating that lymphocyte IP(3) receptors are aggregated underneath certain surface receptor-capped structures(22) . Importantly, the IP(3) receptor (Fig. 1, E and G) appears to be co-localized with ankyrin (Fig. 1, F and H) within surface receptor-capped structures induced by ConA (Fig. 1, E and F) and anti-CD3 antibody (Fig. 1, G and H). Because both anti-CD3 antibody and ConA have been shown to be involved in T cell receptor-mediated signal transduction and lymphocyte activation(23, 24) , these results suggest that the close interaction between IP(3) receptor and ankyrin during ligand-induced receptor capping events may be critically important for IP(3) receptor-mediated internal Ca release at the onset of lymphocyte activation.


Figure 1: Double immunofluorescence staining of IP(3) receptor and ankyrin in ligand-induced lymphocyte-capped structures. A, surface ConA-capped structures induced by fluorescein-labeled ConA. B, intracellular IP(3) receptor staining using rhodamine-labeled mouse monoclonal anti-IP(3) receptor antibody in the same ConA-capped cells shown in A. C, surface CD3-capped structures induced by hamster anti-CD3 antibody followed by fluorescein-labeled rabbit anti-hamster IgG. D, intracellular IP(3) receptor staining using rhodamine-labeled mouse monoclonal anti-IP(3) receptor antibody in the same CD3-capped cells shown in C. E, intracellular IP(3) receptor staining using rhodamine-labeled mouse monoclonal anti-IP(3) receptor antibody in ConA-capped cells induced by unlabeled ConA. F, intracellular ankyrin staining using fluorescein-labeled mouse monoclonal anti-ankyrin antibody in the same ConA-capped cells induced by unlabeled ConA as shown in E. G, intracellular IP(3) receptor staining using rhodamine-labeled mouse monoclonal anti-IP(3) receptor antibody in CD3-capped cells (induced by hamster anti-CD3 antibody plus rabbit anti-hamster IgG). F, intracellular ankyrin staining using fluorescein-labeled mouse monoclonal anti-ankyrin antibody in the same CD3-capped cells (induced by hamster anti-CD3 antibody plus rabbit anti-hamster IgG as shown in G). Arrowheads indicate surface receptor-capped structures and accumulation of intracellular IP(3) receptor and ankyrin.



We have also reported recently that mouse T-lymphoma cell IP(3) receptor (approx260 kDa) is preferentially located in a light density vesicle fraction (15-25% sucrose interface with a density of 1.07 g/ml) containing a unique vesicle population different from Golgi, endoplasmic reticulum, plasma membranes, and lysosomes (12) . Scatchard plot analyses have shown the presence of a high affinity ankyrin-binding site (K(d) of 0.2 nM) on the IP(3) receptor in mouse T-lymphoma cells(12) . Furthermore, we have shown that the binding of ankyrin to the IP(3) receptor-containing vesicles (light density vesicles) significantly modulates IP(3) binding and IP(3)-induced internal Ca release activities (12) .

Using a panel of monoclonal and polyclonal antibodies against IP(3) receptor, we have established that the T-lymphoma cell IP(3) receptor displays immunological cross-reactivity with the rat brain IP(3) receptor(12) . Ankyrin has also been shown to bind to the IP(3) receptor in brain(11) . These data suggest that T-lymphoma cell IP(3) receptor and brain IP(3) receptor share a great deal of structural and functional similarities including ankyrin binding properties. In order to understand the regulatory role of ankyrin in modulating IP(3) receptor-mediated function, it is clearly important to first determine the ankyrin-binding domain of the IP(3) receptor. Because the primary structure of T-lymphoma cell IP(3) receptor is not available, the well established protein sequence of IP(3) receptor obtained from rat and mouse brain (25, 26) has been used for sequence comparison analyses in this study. As shown in Fig. 2, both rat and mouse brain IP(3) receptor contains the sequence GGVGDVLRKPS, located close to the C terminus of the molecule (i.e. at amino acids 2548-2558 of rat brain IP(3) receptor and amino acids 2546-2556 of mouse brain IP(3) receptor). This 11-amino acid peptide shares a great deal of sequence homology with the CD44 ankyrin-binding domain (e.g. GGNGTVEDRKPS), which is involved in the regulation of cell adhesion function(10) . To test whether the sequence GGVGDVLRKPS of the IP(3) receptor is involved in ankyrin binding, we have examined the ability of an 11-amino acid synthetic peptide identical to GGVGDVLRKPS to bind various cytoskeletal proteins. As shown in Fig. 3A, this synthetic peptide binds ankyrin specifically in a dose-dependent manner. The binding of this synthetic peptide to ankyrin is specific, because it does not bind other cytoskeletal proteins such as fodrin or spectrin (Fig. 3A). A control peptide containing a scrambled sequence (GRDVKSPGLVG) with the same amino acid composition as that of the synthetic peptide does not bind to any cytoskeletal proteins tested (e.g. ankyrin, fodrin, and spectrin) (Fig. 3B).


Figure 2: Sequence comparisons between IP(3) receptor and CD44.




Figure 3: Binding of I-labeled cytoskeletal proteins (e.g. ankyrin, spectrin, and fodrin) to synthetic peptides. Various concentrations (20, 40, 60, and 80 ng/ml) of I-labeled cytoskeletal proteins, including ankyrin (bullet), fodrin (box), and spectrin (), were incubated with the nitrocellulose discs coated with either the 11-amino acid peptide (GGVGDVLRKPS) or a scramble peptide (GRDVKSPGLVG) at 4 °C for 4 h as described under ``Materials and Methods.'' Nonspecific binding was determined in the presence of a 100-fold excess of the respective unlabeled cytoskeletal proteins and subtracted from the total binding. The results represent the average of duplicate determinations for each of the ligands used. A, binding of I-labeled cytoskeletal proteins to the 11-amino acid peptide (GGVGDVLRKPS). B, binding of I-labeled cytoskeletal proteins to scramble peptide (GRDVKSPGLVG).



In this study we have found that the 11-amino acid synthetic peptide (GGVGDVLRKPS) competes effectively for the ankyrin-binding site on both purified mouse T-lymphoma cell IP(3) receptor and IP(3) receptor-containing vesicles (light density vesicles). We have determined the apparent inhibition constants (K(i)) to be approx25 and approx50 nM, respectively (Fig. 4A). As a positive control, we have also found that this synthetic peptide competes effectively with CD44 (a well characterized ankyrin-binding protein) for ankyrin binding (Fig. 4B). These findings strongly suggest that the amino acid sequence GGVGDVLRKPS is an important part of the ankyrin-binding domain of T-lymphoma cell IP(3) receptor.


Figure 4: Binding of I-labeled IP(3) receptor, CD44, and IP(3) receptor-containing vesicles to ankyrin. I-Labeled samples (e.g. IP(3) receptor, CD44, or IP(3) receptor-containing vesicles) were incubated with ankyrin in the presence of various concentrations of unlabeled 11-amino acid peptide (GGVGDVLRKPS) as described under ``Materials and Methods.'' The specific binding observed in the absence of any of the competing peptides is designated as 100%. The results represent an average of duplicate determinations for each concentration of the competing peptide used. A, binding of I-labeled IP(3) receptor (bullet) and IP(3) receptor-containing vesicles () to ankyrin. B, binding of I-labeled CD44 to ankyrin in the absence (a) and presence (b) of the competing peptides.



Furthermore, we have confirmed that the binding of ankyrin to the IP(3) receptor in IP(3) receptor-containing vesicles (light density vesicles) causes a remarkable inhibition on IP(3) binding (Table 1) and IP(3)-stimulated internal Ca release (Table 2) as shown previously(12) . Most importantly, we have found that this synthetic peptide (at concentrations ranging from 1 nM to 1 µM, comparable with those used to inhibit ankyrin binding to IP(3) receptor (Fig. 4)) is capable of reversing the inhibitory effects of ankyrin-induced IP(3) binding (Table 1) and IP(3)-mediated Ca release (Table 2) in a concentration-dependent manner. These findings suggest that the 11-amino acid sequence of GGVGDVLRKPS (located close to the C terminus of the IP(3) receptor) resides on the cytoplasmic side (not the luminal side) of IP(3) receptor-containing vesicles in mouse T-lymphoma cells. The exact location of this 11-amino acid ankyrin-binding domain within the peptide of mouse T-lymphoma cell IP(3) receptor remains to be determined. We feel that identification of the ankyrin-binding domain has allowed us to experimentally define the topology of the IP(3) receptor with regard to the side (the cytoplasmic side versus luminal side) on which the 11-amino acid sequence GGVGDVLRKPS resides in the C terminus region. However, computer-generated models (based on limited rat and mouse brain IP(3) receptor sequences) predict that a region such as GGVGDVLRKPS would be located on the luminal side of the Ca storage vesicles(25, 26, 27) . It is possible that there is a differential arrangement of this sequence between mouse T-lymphoma cell IP(3) receptor and brain IP(3) receptors. This point awaits further investigation. We believe, however, that the unique 11-amino acid region GGVGDVLRKPS is not only important for ankyrin binding, but it also plays a pivotal role in the regulation of IP(3) receptor-mediated internal Ca release during lymphocyte activation.






FOOTNOTES

*
This work was supported by National Institutes of Health Grants GM 36353 and CA 66163, a Department of Defense grant, and American Heart Association grants. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked ``advertisement'' in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

§
To whom correspondence should be addressed: Dept. of Cell Biology and Anatomy, School of Medicine, University of Miami, 1600 N.W. 10th Ave., Miami, FL 33101. Tel: 305-547-6985; Fax: 305-545-7166.

(^1)
The abbreviations used are: IP(3), inositol 1,4,5-trisphosphate; ConA, concanavalin A.


ACKNOWLEDGEMENTS

We gratefully acknowledge the assistance of Dr. Gerard J. Bourguignon in the preparation of this manuscript. We also thank Dr. Vinata Lokeshwar for assistance in measuring the binding of CD44 to ankyrin and Dr. Neil Brandt for valuable discussions throughout the course of this project.


REFERENCES

  1. Bennett, V. (1990) Physiol. Rev. 70, 1029-1065 [Free Full Text]
  2. Bourguignon, L. Y. W. (1992) in Encyclopedia of Immunology (Roitt, I. M., and Delves, P. J., eds) pp. 1044-1046, Academic Press, New York
  3. Rossier, M. F., Bird, G. S. J., and Putney, J., Jr. (1991) Biochem. J. 274, 643-650 [Medline] [Order article via Infotrieve]
  4. Bourguignon, L. Y. W., Iida, N., and Jin, H. (1993) Cell Biol. Int. 17, 751-758 [CrossRef][Medline] [Order article via Infotrieve]
  5. Bourguignon, L. Y. W., Walker, G., Suchard, S., and Balazovich, K. (1986) J. Cell Biol. 102, 2115-2124 [Abstract]
  6. Kalomiris, E. L., and Bourguignon, L. Y. W. (1988) J. Cell Biol. 106, 319-327 [Abstract]
  7. Kalomiris, E. L., and Bourguignon, L. Y. W. (1989) J. Biol. Chem. 264, 8113-8119 [Abstract/Free Full Text]
  8. Bourguignon, L. Y. W., Kalomiris, E. L., and Lokeshwar, V. B. (1991) J. Biol. Chem. 266, 11761-11765 [Abstract/Free Full Text]
  9. Lokeshwar, V. B., and Bourguignon, L. Y. W. (1992) J. Biol. Chem. 267, 21551-21557 [Abstract/Free Full Text]
  10. Lokeshwar, V. B., Fregien, N., and Bourguignon, L. Y. W. (1994) J. Cell Biol. 126, 1099-1109 [Abstract]
  11. Jeseph, S. K., and Samanta, S. (1993) J. Biol. Chem. 268, 6477-6486 [Abstract/Free Full Text]
  12. Bourguignon, L. Y. W., Jin, H., Iida, N., Brandt, N., and Zhang, S. H. (1993) J. Biol. Chem. 268, 7290-7297 [Abstract/Free Full Text]
  13. Kraus-Friedmann, N. (1994) Cell Motil. Cytoskeleton 28, 279-284 [Medline] [Order article via Infotrieve]
  14. Bourguignon, L. Y. W., Lokeshwar, V. B., Chen, X., and Kerrick, W. G. L. (1993) J. Immunol. 151, 6634-6644 [Abstract/Free Full Text]
  15. Guillemette, G., Balla, T., Baukal, A. J., Spat, A., and Catt, K. J. (1987) J. Biol. Chem. 262, 1010-1015 [Abstract/Free Full Text]
  16. Bennett, V. (1992) J. Biol. Chem. 267, 8703-8706 [Free Full Text]
  17. Davis, J., Lux, S. E., and Bennett, V. (1989) J. Biol. Chem. 264, 9665-9672 [Abstract/Free Full Text]
  18. Nelson, W. J., and Veshnock, P. (1987) Nature 328, 533-536 [Medline] [Order article via Infotrieve]
  19. Morrow, J. S., Cianci, C. D., Ardito, A. S., and Kashgarian, M. (1989) J. Cell Biol. 108, 455-465 [Abstract]
  20. Flucher, B. E., and Daniels, M. P. (1989) Neuron 3, 163-175 [Medline] [Order article via Infotrieve]
  21. Smith, P. R., Saccomani, G., Joe, E. H., Angelides, K. J., and Benos, D. J. (1991) Proc. Natl. Acad. Sci. U. S. A. 88, 6971-6975 [Abstract]
  22. Khan, A. A., Steiner, J. P., Klein, M. G., Schneider, M. F., and Snyder, S. H. (1992) Science 257, 815-818 [Medline] [Order article via Infotrieve]
  23. Abraham, R. T., Karnitz, L. M., Secrist, J. P., and Leibson, P. J. (1992) Trends Biochem. Sci. 17, 434-438 [Medline] [Order article via Infotrieve]
  24. Bourguignon, L. Y. W., Jy, W., Majercik, M. H., and Bourguignon, G. J. (1988) J. Cell. Biochem. 37, 131-150 [Medline] [Order article via Infotrieve]
  25. Furuichi, T., Yoshikawa, S., Miyawaki, A., Wada, K., Maeda, N., and Mikoshiba, K. (1989) Nature 342, 32-38 [Medline] [Order article via Infotrieve]
  26. Mignery, G. A., Newton, C. L., Archer, B. T., III, and Sudhof, T. C. (1989) J. Biol. Chem. 265, 12679-12685 [Abstract/Free Full Text]
  27. Sudhof, T. C., Newton, C. L., Archer, B. T., III, Ushkaryov, Y. A., and Mignery, G. A. (1991) EMBO J. 10, 3199-3206 [Abstract]

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