Gene structure, chromosomal localization, and expression pattern of Capn12, a new member of the calpain large subunit gene family

We report the identification of mouse Capn12 a new member of the calpain la rge subunit gene family. It possesses potential protease and calcium-bindin g domains, features typical of the classical calpains. In situ hybridizatio n and Northern blot analysis demonstrate that during the anagen phase of th e hair cycle the cortex of the hair follicle is the major expression site o f Capn12 The gene was sequenced in its entirety and consists of 21 exons sp anning 13 kb with an exon-intron structure typical of the calpain gene fami ly. The last exon of the mouse Actn4 gene overlaps the 3' end of Capn12 but in the opposite orientation. This overlap between the two genes is conserv ed in the human genome. Three versions of the Capn12 mRNA transcript were i dentified. They occur as a result of alternative splicing, and two of these encode a protein lacking the C-terminal calmodulin-like domain. Radiation hybrid mapping localized Capn12 to mouse chromosome 7, closely linked to a marker positioned at 10.4 cM. Refined mapping of Capn5, also previously loc alized to chromosome 7, indicated that it was not closely linked to Capn12 mapping tightly linked to a marker positioned at 48.5 cM. (C) 2000 Academic Press.