Peche V, Shekar S, Leichter M, Korte H, Schröder R, Schleicher M, Holak T A, Clemen C S, Ramanath-Y B, Pfitzer G, Karakesisoglou I, Noegel A A
Institute of Biochemistry I, Medical Faculty, University of Cologne, Joseph-Stelzmann-Str. 52, 50931, Köln, Germany.
Cell Mol Life Sci. 2007 Oct;64(19-20):2702-15. doi: 10.1007/s00018-007-7316-3.
Cyclase-associated proteins (CAPs) are evolutionarily conserved proteins with roles in regulating the actin cytoskeleton and in signal transduction. Mammals have two CAP genes encoding the related CAP1 and CAP2. We studied the distribution and subcellular localization of CAP1 and CAP2 using specific antibodies. CAP1 shows a broad tissue distribution, whereas CAP2 is significantly expressed only in brain, heart and skeletal muscle, and skin. CAP2 is found in the nucleus in undifferentiated myoblasts and at the M-line of differentiated myotubes. In PAM212, a mouse keratinocyte cell line, CAP2 is enriched in the nucleus, and sparse in the cytosol. By contrast, CAP1 localizes to the cytoplasm in PAM212 cells. In human skin, CAP2 is present in all living layers of the epidermis localizing to the nuclei and the cell periphery. In in vitro studies, a C-terminal fragment of CAP2 interacts with actin, indicating that CAP2 has the capacity to bind to actin.
环化酶相关蛋白（CAPs）是进化上保守的蛋白质，在调节肌动蛋白细胞骨架和信号转导中发挥作用。哺乳动物有两个编码相关CAP1和CAP2的CAP基因。我们使用特异性抗体研究了CAP1和CAP2的分布及亚细胞定位。CAP1显示出广泛的组织分布，而CAP2仅在脑、心脏、骨骼肌和皮肤中显著表达。在未分化的成肌细胞中，CAP2存在于细胞核中，而在分化的肌管的M线处也有发现。在小鼠角质形成细胞系PAM212中，CAP2在细胞核中富集，在细胞质中稀疏。相比之下，CAP1定位于PAM212细胞的细胞质中。在人类皮肤中，CAP2存在于表皮的所有活层中，定位于细胞核和细胞周边。在体外研究中，CAP2的C末端片段与肌动蛋白相互作用，表明CAP2具有结合肌动蛋白的能力。
