Identification of PKD2L, a human PKD2-related gene: Tissue-specific expression and mapping to chromosome 10q25

Mutations in PKD2 cause autosomal dominant kidney disease (ADPKD). Polycyst in-2, the PKD2 gene product, is an integral membrane glycoprotein of unknow n function. We have identified PKD2L, another member of the; PKD2 gene fami ly. PKD2L is expressed in adult heart and skeletal muscle, brain, spleen, t estis, and retina, and alternative transcripts of 2.4, 2.7, and 3.0 kb are seen. PKD2L shows 56% identity and 76% similarity with polycystin-2 over a 581-amino-acid span; however, the COOH-terminal 65 residues of PKD2L are un related to PKD2. PKD2L is localized to chromosome 10q25 and is excluded as a candidate gene for autosomal recessive polycystic kidney disease, autosom al dominant polycystic liver disease, and the third form of ADPKD. Given th e high degree of homology between PKD2L and PKD2, it is likely that the res pective functions of these proteins are also closely related. (C) 1998 Acad emic Press.