Tissue-specific alternative splicing of the CSE1L/CAS (cellular apoptosis susceptibility) gene

CSE1L/CAS (CAS) is a nuclear transport factor that plays a role in prolifer ation and apoptosis. The CAS gene consists of 25 exons. mRNA homologous ove r its entire length to the yeast homologue CSE1 is the predominant transcri pt in proliferating tissues. Additional mRNAs are generated by alternative splicing in a tissue-specific manner. An extended 3'-end is found in fetal and adult brain, A mRNA containing the 5'-end of CAS up to position 690 and an alternative 3'-end is expressed in trachea and encodes a truncated Ran- binding domain. Fetal liver expresses a mRNA with deletions of a central po rtion of CAS and additional sequences encoded by the last intron, SW480 col on cancer cells express another similar to 1500-base mRNA. Western blot ana lyses of various human tissues and immunohistology of mouse embryos show a correlation of CAS transcripts and CAS protein in different tissues, CAS is oforms may control nuclear transport of tissue-specific proteins.