Phospholipid Scramblase 4 (PLSCR4)

Using the sequence of PLSCR1 as query, Wiedmer et al. (2000) identified an EST containing PLSCR4, and they cloned the full-length cDNA by PCR of a multiple-tissue cDNA library. The deduced 329-amino acid protein contains an N-terminal proline-rich region and a C-terminal Ca(2+)-binding domain. The proline-rich region contains several PxxP motifs that mediate binding to proteins containing SH3 and WW domains. PLSCR4 shares 46% identity with PLSCR1, with most of the identity in the C-terminal region. Northern blot analysis revealed a 4.0-kb transcript expressed at variable levels in all tissues examined except peripheral blood lymphocytes. Compared with PLSCR1, PLSCR2, and PLSCR3, PLSR4 was the only member of this family expressed at detectable levels in brain.