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Characterization of Two Cytosolic Diacylglycerol Kinase Forms
Author(s) -
Chen Qing,
Klemm Nancy,
Jeng Ingming
Publication year - 1993
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1993.tb03279.x
Subject(s) - diacylglycerol kinase , cytosol , activator (genetics) , biochemistry , monoacylglycerol lipase , diglyceride , chemistry , enzyme , biology , protein kinase c , gene , receptor , endocannabinoid system
Two forms of rat brain cytosolic diacylglycerol kinase (EC 2.7.1.107) were separated by heparin‐agarose column chromatography. These forms, designated DGK‐I and DGK‐II, were not interconvertible as determined by rechromatography. DGK‐I and DGK‐II had respective molecular masses of 88 and 180 kDa, as measured by Sepharose 6B chromatography. Both forms preferred diacylglycerol over monoacylglycerol and were insensitive to R59022. DGK‐II, but not DGK‐I, was activated by an activator substance prepared from chicken egg yolk. DGK‐II was activated by a rat brain cytosolic activator and was exclusively sensitive to 5′‐AMP‐mediated inactivation. Further studies revealed that these two forms had the following distinct characteristics: (a) substrate specificity, (b) inhibition by heparin, (c) sensitivity to lysine‐containing polyamino acids, and (d) responses to different phospholipids. In general, DGK‐II was more responsive to various inhibitors and activators, making it a prime candidate for a regulatable enzyme.