Arcuri Cataldo, Giambanco Ileana, Bianchi Roberta, Donato Rosario
Section of Anatomy, Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Via del Giochetto, C.P. 81 Succ. 3, 06122, Perugia, Italy.
Biochim Biophys Acta. 2002 Nov 4;1600(1-2):84-94. doi: 10.1016/s1570-9639(02)00448-x.
S100A11 is a member of a multigenic family of Ca(2+)-modulated proteins of the EF-hand type. We studied the subcellular localization of S100A11 in developing and adult avian skeletal muscle cells by confocal laser scanning microscopy and immunogold cytochemistry to get information about possible functional roles of this protein. Analyses of alpha-actinin, S100A1 and S100B were done in parallel for comparison. Low levels of S100A11 were found in skeletal muscle cells at embryonic day (E) 8. At E12, S100A11 was found in myotubes in the form of fine dots located between Z-discs, and on the sarcolemma and its invaginations. At E15, S100A11 was found on the sarcolemma and internal membranes, likely longitudinal tubules, where the protein was co-localized in part with S100A1 and S100B. At E18 and afterwards, co-localization of the three S100 proteins on internal membranes was almost complete. No evidence for association of S100A11 with the contractile elements of the sarcomeres was obtained. Our data suggests that, like S100A1 and S100B, S100A11 might have a role in the regulation of membrane activities, probably in relation to Ca(2+) fluxes in skeletal muscle cells.
S100A11是EF手型钙调节蛋白多基因家族的成员。我们通过共聚焦激光扫描显微镜和免疫金细胞化学研究了S100A11在发育中和成年禽类骨骼肌细胞中的亚细胞定位，以获取有关该蛋白可能功能作用的信息。同时对α-辅肌动蛋白、S100A1和S100B进行了分析以作比较。在胚胎第8天（E8）的骨骼肌细胞中发现了低水平的S100A11。在E12时，S100A11以位于Z盘之间、肌膜及其内陷处的细点状形式存在于肌管中。在E15时，S100A11存在于肌膜和内膜（可能是纵小管）上，该蛋白部分与S100A1和S100B共定位。在E18及之后，三种S100蛋白在内膜上的共定位几乎完成。未获得S100A11与肌节收缩元件相关联的证据。我们的数据表明，与S100A1和S100B一样，S100A11可能在膜活动的调节中起作用，可能与骨骼肌细胞中的Ca(2+)通量有关。
