Stimulated by retinoic acid gene 6 protein homolog (STRA6)

Function

• may act as a high-affinity cell-surface receptor for the complex retinol-retinol binding protein (RBP/RBP4)
• acts by removing retinol from RBP/RBP4 & transports it across the plasma membrane, where it can be metabolized
• mechanism does not depend on endocytosis
• binds to RBP/RBP4 with high affinity increases cellular retinol uptake from the retinol-RBP complex

Compartment

cell membrane

Alternative splicing

named isoforms=4

Expression

• broad expression
• in adult eye, expressed in sclera, retina, retinal pigment epithelium, & trabecular mashwork
• not expressed in choroid & iris

Pathology

• up-regulated in colorectal cancer cell line WiDr by administration of retinoic acid & in tumors with frequent defects in Wnt-1 signaling
• defects in STRA6 are the cause of syndromic microphthalmia type-9

More general terms

• glycoprotein
• transmembrane 9 protein

Database

• OMIM: https://mirror.omim.org/entry/601186
• UniProt: http://www.uniprot.org/uniprot/Q9BX79.html