Phosphorylation of annexin II tetramer by protein kinase C inhibits aggregation of lipid vesicles by the protein
Annexin II tetramer (A-IIt) is a member of the annexin family of Ca2+ and phospholipid-binding proteins. The ability of this protein to aggregate both phospholipid vesicles and chromaffin granules has suggested a role for the protein in membrane trafficking events such as exocytosis. A-IIt is also a...
Gespeichert in:
Veröffentlicht in: | The Journal of biological chemistry 1992-12, Vol.267 (36), p.25976-25981 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Annexin II tetramer (A-IIt) is a member of the annexin family of Ca2+ and phospholipid-binding proteins. The ability of this
protein to aggregate both phospholipid vesicles and chromaffin granules has suggested a role for the protein in membrane trafficking
events such as exocytosis. A-IIt is also a major intracellular substrate of both pp60src and protein kinase C; however, the
effect of phosphorylation on the activity of this protein is unknown. In the current report we have examined the effect of
phosphorylation on the lipid vesicle aggregation activity of the protein. Protein kinase C catalyzed the incorporation of
2.1 +/- 0.8 mol of phosphate/mol of A-IIt. Phosphorylation of A-IIt caused a dramatic decrease in the rate and extent of lipid
vesicle aggregation without significantly effecting Ca(2+)-dependent lipid binding by the phosphorylated protein. Phosphorylation
of A-IIt increased the A50%(Ca2+) of lipid vesicle aggregation from 0.18 microM to 0.65 mM. Activation of A-IIt phosphorylation,
concomitant with activation of lipid vesicle aggregation, inhibited both the rate and extent of lipid vesicle aggregation
but did not cause disassembly of the aggregated lipid vesicles. These results suggest that protein kinase C-dependent phosphorylation
of A-IIt blocks the ability of the protein to aggregate phospholipid vesicles without affecting the lipid vesicle binding
properties of the protein. |
---|---|
ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/S0021-9258(18)35704-1 |