Immunochemical identification of the pssA gene product as phosphatidylserine synthase I of Chinese hamster ovary cells

FEBS Letters

Saito, Kyoko¹  Akamatsu, Yuzuru¹  Kuge, Osamu¹  Nishijima, Masahiro¹ 

[1] The Department of Biochemistry and Cell Biology, National Institute of Health, 23-1, Toyama 1-chome, Shinjuku-ku, Tokyo 162, Japan

关键词: Phosphatidylserine;    Phosphatidylserine synthase;    pssA;    Phospholipid base-exchange reaction;    Mitochondria-associated membrane;    CHO cell;    CHO;    Chinese hamster ovary;    PS;    phosphatidylserine;    MARCKS;    myristoylated alanine-rich C kinase substrate;    PMSF;    phenylmethylsulfonyl fluoride;    PBS;    phosphate-buffered saline;    MAM;    mitochondria-associated membranes;   

DOI  :  10.1016/0014-5793(96)01049-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have previously shown that a Chinese hamster ovary (CHO) cell mutant defective in phosphatidylserine synthase I recovers the enzyme activity on transfection with a pssA cDNA clone isolated from the parental CHO-K1. The resultant transfectant, CDT-1, exhibited about 20-fold higher specific activity of the enzyme in the membrane fraction than CHO-K1 cells. Polyclonal antibodies against two peptides of the predicted pssA product cross-reacted with a membrane protein having an apparent molecular mass of 42 kDa, which was overproduced in CDT-1 cells. By immunoprecipitation with the antibody, phosphatidylserine synthase I activity as well as the 42-kDa protein was eliminated from solubilized membrane proteins of CDT-1 cells. Both the enzyme activity and the 42-kDa protein of CHO-K1 cells were enriched in the mitochondria-associated membrane fraction and the microsome fraction, but neither was enriched in the mitochondria fraction or the cytosol fraction. These results suggest that the pssA gene encodes phosphatidylserine synthase I.

【 授权许可】

Unknown