sorbin & SH3 domain-containing protein 1 (ponsin, c-Cbl-associated protein, CAP, SH3 domain protein 5, SH3P12, SORBS1, KIAA1296, SH3D5)

Function

• role in tyrosine phosphorylation of CBL
  • links CBL to the insulin receptor
• required for insulin-stimulated glucose transport
• role in formation of actin stress fibers & focal adhesions
• interacts with long isoform of MLLT4/afadin & with VCL
  • MLLT4 & VCL bind to SORBS1 competitively
• interacts with ABL1, CBL, CBLB & INPPL1/SHIP2 via 3rd SH3 domain
  • interaction with ABL1 occurs only after insulin stimulation
  • no effect of insulin on interaction with INPPL1
• interacts with insulin receptor, but dissociates from it following insulin stimulation
• interacts with SCA7, PTK2/p125FAK & flotillin

Structure

• O-glycosylated
• contains 3 SH3 domains
• contains 1 SoHo domain

Compartment

• cell junction, adherens junction, cell membrane
• colocalizes with actin stress fibers
• detected at plasma membrane & in neuronal intranuclear inclusions

Alternative splicing

named isoforms=10

Expression

• widely expressed, highest levels in heart & skeletal muscle

More general terms

• membrane protein
• glycoprotein

Database

• OMIM: https://mirror.omim.org/entry/605264
• UniProt: http://www.uniprot.org/uniprot/Q9BX66.html