Different effects of sphingosine, R59022 and anionic amphiphiles on two diacylglycerol kinase isozymes purified from porcine thymus cytosol

FEBS Letters

Kanoh, Hideo¹  Sakane, Fumio¹  Yamada, Keiko¹ 

[1] Department of Biochemistry, Sapporo Medical College, Sapporo 060, Japan

关键词: Diacylglycerol kinase;    Isozyme;    Purification;    Sphingosine;    R59022;    Thymus;    (Pig);    DGK;    diacylglycerol kinase;   

DOI  :  10.1016/0014-5793(89)81134-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Porcine thymus cytosol contains two immunologically distinct forms of diacylglycerol kinase (DGK) [Yamada, K. and Kanoh, H. (1988) Biochem. J. 255, 601–608]. These 2 DGK species, having apparent molecular masses of 80 and 150 kDa, were purified from the thymus cytosol. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the 150-kDa DGK gave 2 polypeptide bands of 50 and 75 kDa, whereas the 80-kDa DGK yielded a single protein band. The 80-kDa DGK was markedly activated by 10–20 μM sphingosine as well as by the known anionic activators such as phosphatidylserine and deoxycholate. In contrast, the 150-kDa DGK was fully active in the absence of the anionic activators and was strongly inhibited by sphingosine (IC₅₀, 20 μM). The putative DGK inhibitor R59022 inhibited the 80-kDa DGK (IC₅₀, 10 μM), but had little effect on the 150-kDa form. It is therefore clear that in the thymus cytosol there are at least 2 DGK isozymes operating under different control mechanisms.

【 授权许可】

Unknown