Bandorowicz-Pikuła J, Danieluk M, Wrzosek A, Buś R, Buchet R, Pikuła S
Department of Cellular Biochemistry, M. Nencki Institute of Experimental Biology, Warszawa, Poland.
Acta Biochim Pol. 1999;46(3):801-12.
Annexin VI (AnxVI), an Ca2+- and phospholipid-binding protein, interacts in vitro with ATP in a calcium-dependent manner. Experimental evidence indicates that its nucleotide-binding domain which is localized in the C-terminal half of the protein differs structurally from ATP/GTP-binding motifs found in other nucleotide-binding proteins. The amino-acid residues of AnxVI directly involved in ATP binding have not been yet defined. Binding of ATP to AnxVI induces changes in the secondary and tertiary structures of protein, affecting the affinity of AnxVI for Ca2+ and, in consequence, influencing the Ca2+-dependent activities of AnxVI: binding to F-actin and to membranous phospholipids, and self-association of the annexin molecules. These observations suggest that ATP is a functional ligand for AnxVI in vivo, and ATP-sensitive AnxVI may play the role of a factor coupling vesicular transport and calcium homeostasis to cellular metabolism.
膜联蛋白VI（AnxVI）是一种钙和磷脂结合蛋白，在体外以钙依赖的方式与ATP相互作用。实验证据表明，其位于蛋白质C端一半的核苷酸结合结构域在结构上与其他核苷酸结合蛋白中的ATP/GTP结合基序不同。尚未确定AnxVI中直接参与ATP结合的氨基酸残基。ATP与AnxVI的结合会引起蛋白质二级和三级结构的变化，影响AnxVI对Ca2+的亲和力，进而影响AnxVI的钙依赖活性：与F-肌动蛋白和膜磷脂的结合，以及膜联蛋白分子的自缔合。这些观察结果表明，ATP在体内是AnxVI的功能性配体，对ATP敏感的AnxVI可能起到将囊泡运输和钙稳态与细胞代谢偶联的因子的作用。
