Alternative titles; symbolsCHROMOSOME 17 OPEN READING FRAME 38; C17ORF38PHOSPHOINOSITIDE 3-KINASE-GAMMA ADAPTOR PROTEIN, 87-KDp87-PIKAPHGNC Approved Gene Symbol:...
Alternative titles; symbols
HGNC Approved Gene Symbol: PIK3R6
Cytogenetic location: 17p13.1 Genomic coordinates (GRCh38): 17:8,802,721-8,870,002 (from NCBI)
C17ORF38 is a regulatory subunit for phosphoinositide 3-kinase-gamma (Voigt et al., 2006).
▼ Cloning and Expression
Phosphoinositide 3-kinase-gamma contains a catalytic p110-gamma subunit (PIK3CG; 601232) and a p101 regulatory subunit (PIK3R5; 611317). Based on homology to the p101 regulatory subunit, Voigt et al. (2006) used RT-PCR to clone a novel regulatory subunit, p87(PIKAP), from mouse dendritic cell mRNA. Immunofluorescence studies localized p87(PIKAP) to the cytosol in both HEK293 and COS-7 cells. Northern blot analysis detected a 3.2-kb p87(PIKAP) transcript in mouse tissues, with highest expression in heart, moderate expression in most other tissues tested, and barely detectable expression in thymus. A shorter transcript was detected in testis. Voigt et al. (2006) compared relative expression of p87(PIKAP) and PIK3R5 in mouse tissues and found that p87(PIKAP) is expressed in mouse heart at a 5-fold higher level than p101.
▼ Gene Function
By fluorescence imaging and confocal microscopy, Voigt et al. (2006) showed that p87(PIKAP) interacts with PIK3CG. The binding of p87(PIKAP) and PIK3R5 to PIK3CG was mutually exclusive. p87(PIKAP) appeared to bind to PIK3CG with a slightly higher affinity than PIK3R5. Like PIK3R5, p87(PIKAP) interacts with G beta/gamma G proteins (see GNB1, 139380 and GNG2, 606981) and activates PIK3CG downstream from chemokine receptor stimulation. Using coimmunoprecipitation studies in mouse heart tissue, Voigt et al. (2006) showed that p87(PIKAP) interacts with PDE3B (602047), but not at a level sufficient to regulate PDE3B activity.
By genomic sequence analysis, Voigt et al. (2006) mapped the mouse p87(PIKAP) gene to chromosome 11. Based on an alignment of the p87(PIKAP) sequence (GenBank BC125169) with the genomic sequence (build 36.0), the p87(PIKAP) gene maps to chromosome 17.