Targeting of PKCalpha and epsilon in the pituitary: a highly regulated mechanism involving a GD(E)E motif of the V3 region
| Autor: | Alice Vallentin, Corinne Quittau-Prévostel, Alejandra Collazos, Nathalie Delaunay, Dominique Joubert |
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| Rok vydání: | 2003 |
| Předmět: |
Protein Kinase C-alpha
Mutant Protein Kinase C-epsilon Plasma protein binding Biology PKC alpha Models Biological Mice Protein structure Consensus sequence Cell Adhesion Animals Cell adhesion Protein kinase C Cells Cultured Protein Kinase C Cell Biology Cell biology Protein Structure Tertiary Rats Enzyme Activation Isoenzymes Intercellular Junctions Biochemistry Microscopy Fluorescence Pituitary Gland Mutagenesis Site-Directed Calcium Laminin Protein Binding |
| Zdroj: | Journal of cell science. 117(Pt 1) |
| ISSN: | 0021-9533 |
| Popis: | Protein kinase C (PKC) has been implicated in the control of intercellular adhesion. Our previous observation demonstrating that activated PKC alpha (PKCalpha is selectively targeted to cell-cell contacts of pituitary GH3B6 cells supports these findings. The relevance of this observation is further strengthened by the present data establishing that this targeting selectivity also occurs in the pituitary gland. Moreover, a new mechanism involved in the control of PKC targeting is unravelled. We demonstrate that a three amino acid motif located in the V3 region of alpha and epsilon (epsilon (GDE/GEE respectively) is essential for the targeting selectivity of these isoforms because: (1) this motif is absent in delta (delta) and mutated in the natural D294GPKCalpha mutant, which do not exhibit such selectivity, and (2) a GEE to GGE mutation abolishes the selectivity of targeting to cell-cell contacts for epsilon, as it does for the D294G PKCalpha mutant. Thus the GD(E)E motif may be part of a consensus sequence able to interact with shuttle and/or anchoring proteins. GFP-tagged deletion mutants also reveal a new function for the pseudosubstrate in the cytoplasmic sequestration. Together, these data underline the complexity of PKC subcellular targeting in the pituitary, determined by the cell-cell contact, at least for alpha and epsilon |
| Databáze: | OpenAIRE |
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