Chen F, Torres M, Duncan R F
Department of Molecular Pharmacology and Toxicology, University of Southern California School of Pharmacy, Los Angeles 90033, USA.
Biochem J. 1995 Dec 1;312 ( Pt 2)(Pt 2):341-9. doi: 10.1042/bj3120341.
Heat shock treatment of Drosophila melanogaster tissue culture cells causes increased tyrosine phosphorylation of several 44 kDa proteins, which are identified as Drosophila mitogen-activated protein (MAP) kinases. Tyrosine phosphorylation occurs within 5 min, and is maintained at high levels during heat shock. It decreases to basal levels during recovery, concurrent with the repression of heat shock transcription and heat-shock-protein synthesis. The increased MAP kinase tyrosine phosphorylation is parallelled by increased MAP kinase activity. At least two MAP kinases, DmERK-A and DmERK-B, are identified whose tyrosine phosphorylation increases during heat shock. Thus MAP kinase activation is an immediate early response to heat shock, and its increased activity is maintained throughout heat shock treatment. Protracted MAP kinase activation may contribute to heat shock transcription factor phosphorylation and the numerous metabolic alterations that constitute the heat-shock response.
对黑腹果蝇组织培养细胞进行热休克处理会导致几种44 kDa蛋白质的酪氨酸磷酸化增加，这些蛋白质被鉴定为果蝇丝裂原活化蛋白（MAP）激酶。酪氨酸磷酸化在5分钟内发生，并在热休克期间维持在高水平。在恢复过程中它降至基础水平，同时热休克转录和热休克蛋白合成受到抑制。MAP激酶酪氨酸磷酸化的增加与MAP激酶活性的增加平行。至少鉴定出两种MAP激酶，即DmERK-A和DmERK-B，它们的酪氨酸磷酸化在热休克期间增加。因此，MAP激酶激活是对热休克的即时早期反应，并且其增加的活性在整个热休克处理过程中得以维持。持久的MAP激酶激活可能有助于热休克转录因子磷酸化以及构成热休克反应的众多代谢改变。
