Integrin Beta 1 Binding Protein 2 (ITGb1BP2)

The human ITGB1BP2 cDNA encodes a deduced 347-amino acid protein that shares 92% sequence identity with the mouse homolog. Its C terminus contains an acidic region resembling the calreticulin and calsequestrin C-domain, which is known to bind calcium, and the N terminus contains 2 cysteine-rich repeats. The predicted protein also has putative binding sites for SH3 and SH2 domains. Northern blot analysis of human tissues detected restricted expression of a 1.4-kb ITGB1BP2 transcript in skeletal and cardiac muscles. An identical expression pattern was found in mouse tissues. Northern and Western blot analysis of a murine myogenic cell line showed that expression is absent in undifferentiated myoblasts but is turned on in differentiating myotubes and during muscle regeneration.