Xu X, Gilpin B, Iba K, Maier A, Engvall E, Albrechtsen R, Wewer U M
Institute of Molecular Pathology, University of Copenhagen, Denmark.
J Muscle Res Cell Motil. 2001;22(2):121-32. doi: 10.1023/a:1010377325382.
Tetranectin is a C-type lectin that occurs in the mammalian musculoskeletal system. In the present report we describe the first studies on an avian tetranectin. A full-length chicken tetranectin cDNA was isolated. Comparison of the deduced amino acid sequence of chicken tetranectin with mouse and human tetranectin showed an identity of 67 and 68%, respectively. Northern blot analysis demonstrated broad expression of chicken tetranectin mRNA, which was first detected on embryonic day 4. Tetranectin protein was detected in chicken serum and egg yolk. Since muscle is one of few tissues in which tetranectin protein is retained, we examined the distribution of tetranectin in various muscle types in chicken. Myofibers strongly positive for tetranectin were observed in several muscles including m. tibialis ant. and m. sartorius (from embryonic day 10 to adult). Using antibodies to fast and slow myosin heavy chains (MHC) and double immunostaining techniques, we found that tetranectin was restricted to slow (type I) muscle fibers. Similarly only slow intrafusal fibers accumulated tetranectin. The pattern of immunostaining in chickens differs markedly from that seen in mouse muscles, indicating that tetranectin performs a role in muscle that is not associated with a hitherto recognized muscle type or function.
腱生蛋白是一种存在于哺乳动物肌肉骨骼系统中的C型凝集素。在本报告中，我们描述了对禽类腱生蛋白的首次研究。分离出了全长鸡腱生蛋白cDNA。将推导的鸡腱生蛋白氨基酸序列与小鼠和人类腱生蛋白进行比较，分别显示出67%和68%的同一性。Northern印迹分析表明鸡腱生蛋白mRNA广泛表达，在胚胎第4天首次检测到。在鸡血清和蛋黄中检测到了腱生蛋白。由于肌肉是保留腱生蛋白的少数组织之一，我们研究了腱生蛋白在鸡不同肌肉类型中的分布。在包括胫骨前肌和缝匠肌（从胚胎第10天到成年）在内的几块肌肉中观察到了对腱生蛋白呈强阳性的肌纤维。使用抗快肌和慢肌肌球蛋白重链（MHC）抗体以及双重免疫染色技术，我们发现腱生蛋白仅限于慢肌（I型）纤维。同样，只有慢肌梭内纤维积累腱生蛋白。鸡的免疫染色模式与小鼠肌肉中的明显不同，表明腱生蛋白在肌肉中发挥的作用与迄今公认的肌肉类型或功能无关。
