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centaurin-beta-1; Arf-GAP with coiled-coil, ANK repeat & PH domain-containing protein 1; Cnt-b1 (ACAP1, CENTB1, KIAA0050)
Function:
- GTPase-activating protein (GAP) for ADP ribosylation factor 6 (ARF6) required for clathrin-dependent export of proteins from recycling endosomes to trans-Golgi network & cell surface
- GAP activity stimulated by phosphatidylinositol-4,5-bisphosphate (PIP2) & phosphatidic acid
- phosphorylation at Ser-554 by PKB is required for interaction with ITGB1, export of ITGB1 from recycling endosomes to the cell surface & ITGB1-dependent cell migration
- interacts with GTP-bound ARF6
- interacts with third cytoplasmic loop of SLC2A4/GLUT4
- interacts with CLTC
- interacts with GULP1
- forms a complex with GDP-bound ARF6 & GULP1
Structure:
- PH domain binds phospholipids including
a) phosphatidic acid
b) phosphatidylinositol-3-phosphate
c) phosphatidylinositol-3,5-bisphosphate (PIP2)
d) phosphatidylinositol-3,4,5-trisphosphate (PIP3)
- PH domain may mediate ACAP1-binding to PIP2 or PIP3 containing membranes
- contains 3 ANK repeats
- contains 1 Arf-GAP domain
- contains 1 BAR domain
- contains 1 PH domain
Expression:
- highest level in lung & spleen
- low level in heart, kidney, liver & pancreas
Notes:
- cells overexpressing ACAP1 show an accumulation of ITGB1 in recycling endosomes & inhibition of stimulation- dependent cell migration
- cells with reduced levels of ACAP1 or AKT1 & AKT2 show inhibition of stimulation-dependent cell migration
- cells overexpressing ACAP1 & PIP5K1C show formation of tubular structures derived from endosomal membranes
Related
pleckstrin homology [PH] domain
pleckstrin; platelet p47 protein (PLEK P47)
General
ankyrin repeat domain protein (ANKRD)
centaurin beta
phosphoprotein
Properties
SIZE: entity length = 740 aa
MW = 82 kD
COMPARTMENT: cytoplasm
MOTIF: formation of endosomal tubules when overexpressed with PIP5K1C {1-382}
MOTIF: BAR {1-226}
PH domain {265-360}
GULP1 interaction {405-740}
MOTIF: Arf-GAP domain
NAME: Arf-GAP domain
SITE: 405-527
Zn finger C4-type
SITE: 420-443
EFFECTOR-BOUND: Zn+2
Ser phosphorylation site {S554}
ankyrin repeat
NAME: ankyrin repeat
SITE: 606-635
ankyrin repeat
NAME: ankyrin repeat
SITE: 639-668
ankyrin repeat
NAME: ankyrin repeat
SITE: 672-702
Database Correlations
OMIM 607763
UniProt Q15027
PFAM correlations
Entrez Gene 9744
Kegg hsa:9744
References
UniProt :accession Q15027