Yang Xiao-Mei, Hou Li-Jing, Dong Du-Juan, Shao Hong-Lian, Wang Jin-Xing, Zhao Xiao-Fan
School of Life Sciences, Shandong University, Jinan, China.
Arch Insect Biochem Physiol. 2006 May;62(1):1-10. doi: 10.1002/arch.20115.
Cathepsin B-like proteinase (HCB, EC 3.4.22.1) is expressed in Helicoverpa armigera oocytes and adult fat bodies. Previous work has revealed that HCB plays a key role in the degradation of yolk proteins during embryogenesis. This study investigated the function and regulatory activation of HCB in adult fat bodies during aging and oogenesis. The HCB transcript was detected at all stages from larval to adult fat bodies with Northern blot analysis. Pro-HCB was also detected in fat bodies at these stages with an immunoblot assay using a monoclonal antibody against HCB. However, mature HCB and its activity were only detected in fat bodies of pre-adults and adults. This evidence suggested that HCB is regulated post-translationally by activation of the pro-enzyme during the pupa-adult metamorphosis. The activation of HCB was coupled with the expression of hormone receptor 3 (HHR3), and was up-regulated by the ecdysteroid agonist, RH-2485, suggesting that HCB activation is related to the ecdysone regulatory system. The decomposition of the adult fat bodies during aging and oogenesis was found to occur via programmed cell death, in which HCB took part.
组织蛋白酶B样蛋白酶（HCB，EC 3.4.22.1）在棉铃虫的卵母细胞和成虫脂肪体中表达。先前的研究表明，HCB在胚胎发育过程中卵黄蛋白的降解中起关键作用。本研究调查了衰老和卵子发生过程中HCB在成虫脂肪体中的功能及调控激活机制。通过Northern印迹分析在从幼虫到成虫脂肪体的所有阶段均检测到了HCB转录本。利用抗HCB单克隆抗体通过免疫印迹分析在这些阶段的脂肪体中也检测到了前体HCB。然而，仅在成虫前期和成虫的脂肪体中检测到了成熟的HCB及其活性。这一证据表明，在蛹-成虫变态过程中，HCB通过前体酶的激活在翻译后水平受到调控。HCB的激活与激素受体3（HHR3）的表达相关，并且被蜕皮甾类激动剂RH-2485上调，这表明HCB的激活与蜕皮激素调节系统有关。研究发现，在衰老和卵子发生过程中，成虫脂肪体的分解是通过程序性细胞死亡发生的，HCB参与其中。
