Brown Daniel D, Christine Kathleen S, Showell Christopher, Conlon Frank L
Department of Biology, UNC-Chapel Hill, Chapel Hill, North Carolina 27599-3280, USA.
Genesis. 2007 Nov;45(11):667-78. doi: 10.1002/dvg.20340.
The small heat shock protein Hsp27 has been shown to be involved in a diverse array of cellular processes, including cellular stress response, protein chaperone activity, regulation of cellular glutathione levels, apoptotic signaling, and regulation of actin polymerization and stability. Furthermore, mutation within Hsp27 has been associated with the human congenital neuropathy Charcot-Marie Tooth (CMT) disease. Hsp27 is known to be expressed in developing embryonic tissues; however, little has been done to determine the endogenous requirement for Hsp27 in developing embryos. In this study, we show that depletion of XHSP27 protein results in a failure of cardiac progenitor fusion resulting in cardia bifida. Furthermore, we demonstrate a concomitant disorganization of actin filament organization and defects in myofibril assembly. Moreover, these defects are not associated with alterations in specification or differentiation. We have thus demonstrated a critical requirement for XHSP27 in developing cardiac and skeletal muscle tissues.
小热休克蛋白Hsp27已被证明参与多种细胞过程，包括细胞应激反应、蛋白质伴侣活性、细胞内谷胱甘肽水平的调节、凋亡信号传导以及肌动蛋白聚合和稳定性的调节。此外，Hsp27内的突变与人类先天性神经病变遗传性运动感觉神经病（CMT）疾病有关。已知Hsp27在发育中的胚胎组织中表达；然而，关于确定Hsp27在发育胚胎中的内源性需求方面做得很少。在本研究中，我们表明XHSP27蛋白的缺失导致心脏祖细胞融合失败，从而导致心脏裂。此外，我们证明了肌动蛋白丝组织同时紊乱以及肌原纤维组装缺陷。而且，这些缺陷与细胞命运决定或分化的改变无关。因此，我们证明了XHSP27在发育中的心脏和骨骼肌组织中的关键需求。
