Oncoprotein Induced Transcript 3 (OIT3)

OIT3 contains one EGF-like domain and one ZP domain. It may be involved in hepatocellular function and development. OIT3 is liver-specific and is expressed only in the hepatocytes; down-regulated in hepatocellular carcinoma (HCC) and HCC cell lines. LZP contains an N-terminal signal peptide, followed by 3 epidermal growth factor (EGF)-like domains and a zona pellucida (ZP) domain in its C-terminal region. LZP also contains several N-glycosylation sites.

The 546-amino acid mouse Lzp protein shares 89% identity with human LZP. Northern blot analysis of several human tissues detected a 2.4-kb transcript only in liver. Northern blot analysis of whole mouse embryos detected 2 Lzp variants that differed in the length of the UTR and the poly(A) signal used.