Stephens R E, Prior G
Marine Biological Laboratory, Woods Hole, MA 02543.
J Cell Sci. 1992 Dec;103 ( Pt 4):999-1012. doi: 10.1242/jcs.103.4.999.
Serotonin, an activator of adenylate cyclase, stimulates motility in molluscan gill cilia and sperm flagella. To determine and compare potential targets of cAMP action, dynein was prepared from the lateral gill.cilia and sperm flagella of the mussel Mytilus edulis and the clam Spisula solidissima. In the flagella of both species, high-salt extraction removes about half of the ATPase activity, half of the alpha and beta heavy chains, and the outer arms. The dynein from both species sediments at 18-20 S, contains two or three intermediate chains, and three light chains. High-salt plus detergent removes most of the remaining dynein ATPase, alpha and beta heavy chains, and inner arms, also yielding a stable 18-20 S particle. In gill cilia of both species, high-salt extraction removes only 12-18% of the ATPase, up to 1/3 of the alpha heavy chains, an equivalent amount of beta heavy chain, and a subset of the outer arms. The dynein sediments at 18-20 S and, in Spisula, the heavy, intermediate, and light chains precisely co-sediment. High-salt plus detergent removes another 1/3 of the alpha heavy chains, an equivalent amount of beta heavy chain, and the remaining outer arms. The ATPase sediments mainly as a 13-14 S form showing considerable dissociation of co-sedimenting intermediate and light chains. The inner arms and at least half of the ciliary dynein ATPase activity remain unextractable, corresponding in mass mainly to an apparent beta heavy chain that is vanadate-cleavable. Cyclic AMP-dependent, calcium-independent phosphorylation takes place on specific dynein light chains in cilia but on only the dynein alpha heavy chain in flagella. Pre-activation of the flagella prevents subsequent addition of labeled phosphate. Phosphorylation has no effect on the steady-state ATPase properties. The single phosphate added to the flagellar alpha chain is located within the LUV1 vanadate photocleavage fragment. Considering the probable locus of the light chains and the site of the alpha heavy chain phosphorylation, both beyond the active site and toward the base of the molecule, these distinct phosphorylations may regulate dynein action by modulating arm flexibility or interaction.
血清素作为腺苷酸环化酶的激活剂，可刺激软体动物鳃纤毛和精子鞭毛的运动。为了确定并比较环磷酸腺苷（cAMP）作用的潜在靶点，从紫贻贝和坚实拟滨螺的鳃外侧纤毛及精子鞭毛中制备了动力蛋白。在这两种物种的鞭毛中，高盐提取可去除约一半的ATP酶活性、一半的α和β重链以及外臂。来自这两种物种的动力蛋白在18 - 20 S沉降，包含两条或三条中间链以及三条轻链。高盐加去污剂可去除大部分剩余的动力蛋白ATP酶、α和β重链以及内臂，也产生一种稳定的18 - 20 S颗粒。在这两种物种的鳃纤毛中，高盐提取仅去除12 - 18%的ATP酶、高达1/3的α重链、等量的β重链以及一部分外臂。动力蛋白在18 - 20 S沉降，在拟滨螺中，重链、中间链和轻链精确共沉降。高盐加去污剂可去除另外1/3的α重链、等量的β重链以及剩余的外臂。ATP酶主要以13 - 14 S的形式沉降，显示共沉降的中间链和轻链有相当程度的解离。内臂以及至少一半的纤毛动力蛋白ATP酶活性仍无法提取，其质量主要对应于一条可被钒酸盐切割的表观β重链。环磷酸腺苷依赖性、钙非依赖性磷酸化发生在纤毛中特定的动力蛋白轻链上，但仅发生在鞭毛中的动力蛋白α重链上。鞭毛的预激活可阻止随后添加标记的磷酸盐。磷酸化对稳态ATP酶特性没有影响。添加到鞭毛α链上的单个磷酸盐位于LUV1钒酸盐光裂解片段内。考虑到轻链的可能位置以及α重链磷酸化的位点，两者都在活性位点之外且朝向分子基部，这些不同的磷酸化可能通过调节臂的柔韧性或相互作用来调节动力蛋白的作用。
