CLONING OF A NEW MEMBER OF THE INSULIN GENE SUPERFAMILY (INSL4) EXPRESSED IN HUMAN PLACENTA

A new member of the insulin gene superfamily was identified by screeni ng a subtracted cDNA library of first-trimester human placenta and, he nce, was tentatively named early placenta insulin-like peptide (EPIL). In this paper, we report the cloning and sequencing of the EPIL cDNA and the EPIL gene (INSL4). Comparison of the deduced amino acid sequen ce of the early placenta insulin-like peptide revealed significant ove rall and structural homologies with members of the insulin-like hormon e superfamily. Moreover, the organization of the early placenta insuli n-like gene, which is composed of two exons and one intron, is similar to that of insulin and relaxin. By in situ hybridization, the INSL4 g ene was assigned to band p24 of the short arm of chromosome 9. RT-PCR analysis of EPIL tissue distribution revealed that its transcripts are expressed in the placenta and uterus. (C) 1995 Academic Press, Inc.