Klemenz R, Andres A C, Fröhli E, Schäfer R, Aoyama A
Department of Pathology, University of Zürich, Switzerland.
J Cell Biol. 1993 Feb;120(3):639-45. doi: 10.1083/jcb.120.3.639.
Stress induces the synthesis of several large and small heat shock proteins (hsp's). Two related small hsp's, hsp25 and alpha B crystallin exist in mice. alpha B crystallin is an abundant protein in several tissues even in the absence of stress. Particularly high amounts accumulate in the eye lens. Here we show that hsp25 is likewise constitutively expressed in many normal adult tissues. In the absence of stress the protein is most abundant in the eye lens, heart, stomach, colon, lung, and bladder. The stress-independent expression pattern of the two small hsp's is distinct. In several tissues the amount of hsp25 exceeds that accumulating in NIH 3T3 fibroblasts in response to heat stress. hsp25, like alpha B crystallin, exists in a highly aggregated form in the eye lens. The expression of hsp25 and alpha B crystallin in normal tissues suggests an essential, but distinct function of the two related proteins under standard physiological conditions.
应激可诱导多种大小不同的热休克蛋白（hsp）的合成。小鼠体内存在两种相关的小hsp，即hsp25和αB晶状体蛋白。即使在无应激状态下，αB晶状体蛋白在多种组织中也是一种丰富的蛋白质。在眼晶状体中积累的量尤其高。在此我们表明，hsp25同样在许多正常成年组织中组成性表达。在无应激状态下，该蛋白在眼晶状体、心脏、胃、结肠、肺和膀胱中最为丰富。这两种小hsp的非应激依赖性表达模式是不同的。在几种组织中，hsp25的量超过了NIH 3T3成纤维细胞在热应激反应中积累的量。与αB晶状体蛋白一样，hsp25在眼晶状体中以高度聚集的形式存在。hsp25和αB晶状体蛋白在正常组织中的表达表明这两种相关蛋白在标准生理条件下具有重要但不同的功能。
