A CHINESE-HAMSTER CDNA-ENCODING A PROTEIN ESSENTIAL FOR PHOSPHATIDYLSERINE SYNTHASE-I ACTIVITY

作者：KUGE O; NISHIJIMA M^*; AKAMATSU Y

来源：Journal of Biological Chemistry, 1991, 266(35): 24184-24189.

A phosphatidylserine-auxotrophic mutant of cultured Chinese hamster ovary (CHO) cells, PSA-3, is defective in phosphatidylserine synthase I activity. Transfection of PSA-3 cells with a cDNA expression library of CHO-K1 (the parent of PSA-3) yielded a phosphatidylserine-prototrophic transformant with normal phosphatidylserine synthase I activity. Using a cDNA segment retrieved from the transformant as a probe, a cDNA clone (pssA) responsible for phosphatidylserine prototrophy was isolated from the original cDNA library by colony filter hybridization. Introduction of the pssA cDNA into PSA-3 cells restored the phosphatidylserine content, and the resultant transformant exhibited 15-fold higher specific phosphatidylserine synthase I activity than CHO-KI cells. The nucleotide sequence of the pssA cDNA contained a single long open reading frame capable of encoding a protein of 471 amino acid residues with several putative membrane-spanning domains. Our results indicated that the pssA cDNA encodes an integral membrane protein essential for phosphatidylserine synthase I activity.

• 出版日期1991-12-15