Manchado Manuel, Salas-Leiton Emilio, Infante Carlos, Ponce Marian, Asensio Esther, Crespo Aniela, Zuasti Eugenia, Cañavate José Pedro
IFAPA Centro El Toruño, Junta de Andalucía, Camino Tiro de pichón s/n, 11500 El Puerto de Santa María, Cádiz, Spain.
Gene. 2008 Jun 15;416(1-2):77-84. doi: 10.1016/j.gene.2008.03.007. Epub 2008 Mar 26.
HSP90 proteins are chaperones that play a pivotal role in controlling multiple regulatory pathways such as stress defense, hormone signalling, cell cycle control, cell proliferation and differentiation, and apoptosis. In this study, two cDNAs encoding for cytosolic HSP90, referred to as HSP90AA and HSP90AB, have been sequenced. Main features and sequence identities with other fish and mammals are described. Phylogenetic analysis grouped both genes into two separate clusters with their fish and mammalian counterparts. Expression profiles during larval development and in juvenile tissues were analyzed using a real-time PCR approach. In juvenile fish, HSP90AB was constitutively expressed with lower transcript levels in skeletal muscle. In contrast, HSP90AA was mainly expressed in heart, skeletal muscle and skin. During metamorphosis, HSP90AB mRNA levels did not change whereas HSP90AA transcripts decreased significantly at the beginning of metamorphosis with the lowest mRNA levels at the metamorphosis climax. Due to the role of thyroid hormones (THs) on sole metamorphosis, the transcriptional regulation of HSP90 genes by THs was evaluated. Larvae exposed to the goitrogen thiourea (TU) exhibited higher HSP90AA mRNA levels than untreated control. Moreover, adding exogenous T4 hormone to TU-treated larvae restored the steady-state levels with respect to the untreated control. Unlike HSP90AA, the transcript levels of HSP90AB did not vary under any treatments. The response of both HSP90 genes to thermal stress in post-metamorphic individuals was also studied. A heat shock treatment (+7.9 degrees C for 1 h) rapidly activated HSP90AA (but not HSP90AB) transcription, reaching a peak after 30 min and declining expression levels progressively in the following 24 h. No significant changes in HSP90AA or HSP90AB transcript levels after a cold shock (-10 degrees C for 1 h) were observed. Overall, these results demonstrate that HSP90AA transcription is down-regulated by THs and up-regulated after a heat shock in Senegalese sole.
热休克蛋白90（HSP90）是一种分子伴侣，在控制多种调节途径中起关键作用，如应激防御、激素信号传导、细胞周期控制、细胞增殖与分化以及细胞凋亡。在本研究中，对编码胞质HSP90的两个cDNA进行了测序，分别称为HSP90AA和HSP90AB。描述了它们的主要特征以及与其他鱼类和哺乳动物的序列同源性。系统发育分析将这两个基因与它们在鱼类和哺乳动物中的对应基因归为两个独立的簇。使用实时PCR方法分析了幼体发育过程中和幼鱼组织中的表达谱。在幼鱼中，HSP90AB组成性表达，在骨骼肌中的转录水平较低。相比之下，HSP90AA主要在心脏、骨骼肌和皮肤中表达。在变态过程中，HSP90AB的mRNA水平没有变化，而HSP90AA的转录本在变态开始时显著下降，在变态高峰期达到最低mRNA水平。由于甲状腺激素（THs）对塞内加尔鳎变态的作用，评估了THs对HSP90基因的转录调控。暴露于甲状腺肿剂硫脲（TU）的幼体比未处理的对照表现出更高的HSP90AA mRNA水平。此外，向TU处理的幼体中添加外源性T4激素可使稳态水平恢复到未处理对照的水平。与HSP90AA不同，HSP90AB的转录水平在任何处理下均无变化。还研究了变态后个体中两个HSP90基因对热应激的反应。热休克处理（+7.9℃ 1小时）迅速激活HSP90AA（但不激活HSP90AB）转录，30分钟后达到峰值，并在随后的24小时内表达水平逐渐下降。冷休克（-10℃ 1小时）后，未观察到HSP90AA或HSP90AB转录水平有显著变化。总体而言，这些结果表明，在塞内加尔鳎中，HSP90AA的转录受THs下调，并在热休克后上调。
