Identification of two phosphorylated threonines in the tail region of Dictyostelium myosin II.
Identification of two phosphorylated threonines in the tail region of Dictyostelium myosin II.
复制标题
盘基网柄菌肌球蛋白 II 尾部两个磷酸化苏氨酸的鉴定。
DOI：
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发表时间：
1988
影响因子：
4.8
通讯作者：
G. Côté
中科院分区：
文献类型：
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作者：
J. Vaillancourt;C. Lyons;G. Côté
我们先前已经纯化并表征了一种使苏氨酸残基磷酸化的网囊藻肌球蛋白II重链激酶（Dictyosterosis myosin II heavy chain kinase）（Letté，G. P.，和Bukiejko，U.（1987）J.Biol.Chem.262，1065-1072）。磷酸化的苏氨酸位于一个34 kDa的片段内，该片段可以选择性地从网囊藻肌球蛋白II尾部的羧基末端裂解。胰蛋白酶和胰凝乳蛋白酶的34 kDa片段磷酸化的激酶，现在已经进行了分离和测序所得的磷酸肽。已经鉴定了两个磷酸化的苏氨酸残基，对应于网囊藻肌球蛋白II重链的完整氨基酸序列中的残基1833和2029。这些氨基酸分别为87和283个残基，远离网囊藻肌球蛋白II重链的羧基末端，并且存在于似乎是α-螺旋卷曲螺旋的尾部部分中。相比之下，三个阿米巴肌球蛋白II重链磷酸化位点位于尾部羧基末端尖端的小球状结构域中，彼此相距10个残基之内（Litté，G. P.，罗宾逊，E.一、Appella，E.，和Korn，E. D.（1984）J.Biol.Chem.259，12781-12787）。这表明，重链磷酸化抑制肌动蛋白激活的ATP酶活性和两种肌球蛋白的粘附形成特性的机制可能是完全不同的。
We have previously purified and characterized a Dictyostelium myosin II heavy chain kinase which phosphorylates threonine residues (Côté, G. P., and Bukiejko, U. (1987) J. Biol. Chem. 262, 1065-1072). The phosphorylated threonines are located within a 34-kDa fragment which can be selectively cleaved from the carboxyl terminal end of the Dictyostelium myosin II tail. Tryptic and chymotryptic digests of the 34-kDa fragment phosphorylated with the kinase have now been performed and the resulting phosphopeptides isolated and sequenced. Two phosphorylated threonine residues have been identified, corresponding to residues 1833 and 2029 in the complete amino acid sequence of the Dictyostelium myosin II heavy chain. These amino acids are 87 and 283 residues, respectively, distant from the carboxyl terminus of the Dictyostelium myosin II heavy chain and are present in sections of the tail which seem to be alpha-helical coiled coils. In contrast, the three Acanthamoeba myosin II heavy chain phosphorylation sites are located within 10 residues of each other in a small globular domain at the carboxyl terminal tip of the tail (Côté, G. P., Robinson, E. A., Appella, E., and Korn, E. D. (1984) J. Biol. Chem. 259, 12781-12787). This suggests that the mechanism by which heavy chain phosphorylation inhibits the actin-activated ATPase activity and filament-forming properties of the two myosins may be quite different.