Yang Yumin, Zhao Dan, Zhou Liqing, Zhang Tianshi, Liu Zhihong, Wu Biao, Yu Tao, Zheng Yanxin, Sun Xiujun
Fisheries College, Zhejiang Ocean University, Zhoushan 316022, China.
Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China.
Biology (Basel). 2022 Mar 16;11(3):453. doi: 10.3390/biology11030453.
Paramyosin is an important myofibrillar protein in molluscan smooth muscle. The full-length cDNA encoding paramyosin has been identified from Yesso scallop . The length of paramyosin molecule has been found to be 3715 bp, which contains an open reading frame (ORF) of 2805 bp for 934 amino acid residues. Characterization of paramyosin reveals the typical structural feature of coiled-coil protein, including six α-helix (α1-α6) and one coil (η) structures. Multiple phosphorylation sites have been predicted at the N-terminus of paramyosin, representing the unique phosphorylation sites in scallops. The highest levels of mRNA and protein expression of paramyosin have been found in foot and the smooth adductor muscle. According to whole-mount in situ hybridization (WISH), strong paramyosin mRNA signals were detected in the symmetric positions of anterior and posterior adductor muscles at late larval stages. These findings support that paramyosin may serve as the most important components for myogenesis and catch regulation in scallops. The present findings will not only help uncover the potential function of myofibrillar proteins in molluscs but also provide molecular evidence to infer evolutionary relationships among invertebrates.
副肌球蛋白是软体动物平滑肌中一种重要的肌原纤维蛋白。已从虾夷扇贝中鉴定出编码副肌球蛋白的全长cDNA。发现副肌球蛋白分子长度为3715 bp，其中包含一个2805 bp的开放阅读框（ORF），对应934个氨基酸残基。副肌球蛋白的特征揭示了卷曲螺旋蛋白的典型结构特征，包括六个α螺旋（α1-α6）和一个卷曲（η）结构。在副肌球蛋白的N端预测到多个磷酸化位点，这是扇贝特有的磷酸化位点。在足部和平滑的闭壳肌中发现副肌球蛋白的mRNA和蛋白表达水平最高。根据全胚胎原位杂交（WISH），在幼虫后期的前后闭壳肌对称位置检测到强烈的副肌球蛋白mRNA信号。这些发现支持副肌球蛋白可能是扇贝肌发生和捕捉调节的最重要成分。目前的发现不仅有助于揭示软体动物中肌原纤维蛋白的潜在功能，还为推断无脊椎动物之间的进化关系提供分子证据。
