A major transmembrane protein of Golgi-derived COPI-coated vesicles involved in coatomer binding
| Autor: | M Ravazzola, M Amherdt, F. Lottspeich, J B Helms, Felix T. Wieland, Martina Bremser, K Sohn, Klaus Fiedler, L. Orci |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
DNA
Complementary Molecular Sequence Data Coated Vesicles Fluorescent Antibody Technique Golgi Apparatus Receptors Cytoplasmic and Nuclear CHO Cells Coatomer Protein Clathrin symbols.namesake Cricetinae Animals Amino Acid Sequence Cloning Molecular Microscopy Immunoelectron Integral membrane protein Golgi membrane biology KKXX Vesicle Membrane Proteins Articles Cell Biology COPI Golgi apparatus Cell biology Molecular Weight Coatomer biology.protein symbols |
| Zdroj: | The Journal of Cell Biology |
| ISSN: | 1540-8140 0021-9525 |
| Popis: | Formation of non-clathrin-coated vesicles requires the recruitment of several cytosolic factors to the Golgi membrane. To identify membrane proteins involved in this budding process, a highly abundant type I transmembrane protein (p23) was isolated from mammalian Golgi-derived COPI-coated vesicles, and its cDNA was cloned and sequenced. It belongs to the p24 family of proteins involved in the budding of transport vesicles (Stamnes, M.A., M.W. Craighead, M.H. Hoe, N. Lampen, S. Geromanos, P. Tempst, and J.E. Rothman. 1995. Proc. Natl. Acad. Sci. USA. 92:8011-8015). p23 consists of a large NH2-terminal luminal domain and a short COOH-terminal cytoplasmic tail (-LRRFFKAKKLIE-CO2-) that shows similarity, but not identity, with the sequence motif-KKXX-CO2-, known as a signal for retrieval of escaped ER-resident membrane proteins (Jackson, M.R., T. Nilsson, and P.A. Peterson. 1990. EMBO (Eur. Mol. Biol. Organ.) J. 9:3153-3162; Nilsson, T., M. Jackson, and P.A. Peterson. 1989. Cell. 58:707-718). The cytoplasmic tail of p23 binds to coatomer with similar efficiency as known KKXX motifs. However, the p23 tail differs from the KKXX motif in having an additional motif needed for binding of coatomer. p23 is localized to Golgi cisternae and, during vesicle formation, it concentrates into COPI-coated buds and vesicles. Biochemical analysis revealed that p23 is enriched in vesicles by a factor of approximately 20, as compared with the donor Golgi fraction, and is present in amounts stoichiometric to the small GTP-binding protein ADP-ribosylation factor (ARF) and coatomer. From these data we conclude that p23 represents a Golgi-specific receptor for coatomer involved in the formation of COPI-coated vesicles. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|