Three new types of Apaf-1 in mammalian cells

Apaf-1, the human C. elegans Ced-4 homologue, plays a crucial role in mitoc hondrial mediated apoptosis. To determine whether a mutant Apaf-1 is involv ed in the pathogenesis of malignant lymphomas, we performed sequence analys is of its transcriptional gene product. Therefore, cDNAs coding for Apaf-1 were examined in six lymphoma derived cell lines, in three non-lymphoid tum or cell lines, as well as in peripheral blood lymphocytes and in tissue fro m heart, kidney, and liver by RT-PCR, These studies did not disclose the ex pected tumor related alterations but led instead to the identification of t hree novel forms of Apaf-1, These forms vary in length, but contain all fun ctional domains formerly characterized in the Apaf-1 protein. The results i ndicate that the previously published sequence is not the Apaf-1 form most widely expressed. (C) 1999 Academic Press.