Department of Biology, Central Michigan University, Mount Pleasant, MI 48859, USA.
Department of Pharmacology and Cancer, Duke University Medical Center, Durham, NC 27708, USA.
Cells. 2019 Jul 21;8(7):758. doi: 10.3390/cells8070758.
Copines make up a family of calcium-dependent, phospholipid-binding proteins found in numerous eukaryotic organisms. Copine proteins consist of two C2 domains at the N-terminus followed by an A domain similar to the von Willebrand A domain found in integrins. We are studying copine protein function in the model organism, , which has six copine genes, . Previous research showed that cells lacking the gene exhibited a cytokinesis defect, a contractile vacuole defect, and developmental defects. To provide insight into the role of CpnA in these cellular processes, we used column chromatography and immunoprecipitation to isolate proteins that bind to CpnA. These proteins were identified by mass spectrometry. One of the proteins identified was actin. Purified CpnA was shown to bind to actin filaments in a calcium-dependent manner in vitro. cells exhibited defects in three actin-based processes: chemotaxis, cell polarity, and adhesion. These results suggest that CpnA plays a role in chemotaxis and adhesion and may do so by interacting with actin filaments.
Copines 是一组钙依赖性磷脂结合蛋白，存在于许多真核生物中。Copine 蛋白由 N 端的两个 C2 结构域和一个 A 结构域组成，A 结构域类似于整合素中的 von Willebrand A 结构域。我们正在研究模式生物 中的 copine 蛋白功能，该生物有六个 copine 基因。先前的研究表明，缺乏 基因的细胞表现出胞质分裂缺陷、收缩泡缺陷和发育缺陷。为了深入了解 CpnA 在这些细胞过程中的作用，我们使用柱层析和免疫沉淀来分离与 CpnA 结合的蛋白质。这些蛋白质通过质谱鉴定。鉴定出的一种蛋白质是肌动蛋白。体外实验表明，纯化的 CpnA 以钙离子依赖的方式与肌动蛋白丝结合。 细胞在三种基于肌动蛋白的过程中表现出缺陷：趋化性、细胞极性和黏附。这些结果表明 CpnA 在趋化性和黏附中发挥作用，可能通过与肌动蛋白丝相互作用来实现。
