Dimerization of the highly conserved light chain shared by dynein and myosin V
Dimerization of the highly conserved light chain shared by dynein and myosin V
复制标题
DOI：
10.1074/jbc.272.33.20929
复制
发表时间：
1997-08-15
影响因子：
4.8
通讯作者：
King, SM
中科院分区：
文献类型：
--
作者：
Benashski, SE;Harrison, A;King, SM
最初在衣原体鞭毛动力蛋白中鉴定的M-r 8，000轻链也是细胞质动力蛋白和肌球蛋白V两者的组分，此外，这种小蛋白已经被牵连为神经元一氧化氮合酶的抑制剂，表明它可能在细胞内发挥多种调节作用。4-二硝基苯显示，该轻链原位以二聚体形式存在。使用两种额外的胺选择性交联试剂（亚胺酸二甲酯和辛二酸二琥珀酰亚胺酯）证实了该观察结果。当表达为与麦芽糖结合蛋白的C-末端融合物时，轻链的存在导致重组分子二聚化。含有截短轻链的融合物的分析鉴定了预测的两亲性螺旋（残基14-32）足以引起二聚化;交联需要第二螺旋段（残基33-46），一起呈现的数据表明两条轻链相互作用以形成平行的二聚体结构，这种安排具有重要意义的潜在功能，这种高度保守的分子，并提出了一种机制，它可能解离一氧化氮合酶。
The M-r 8,000 light chain originally identified in Chlamydomonas flagellar dynein is also a component of both cytoplasmic dynein and myosin V, Furthermore, this small protein has been implicated as an inhibitor of neuronal nitric oxide synthase, suggesting that it may play multiple regulatory roles within the cell, Covalent cross-linking of both dynein and myosin V using 1,5-difluoro-2,4-dinitrobenzene revealed that this light chain exists as a dimer in situ, This observation was confirmed using two additional amine-selective crosslinking reagents (dimethyl pimelimidate and disuccinimidyl suberate). When expressed as a C-terminal fusion with maltose-binding protein, the presence of the light chain caused the recombinant molecule to dimerize. Analysis of fusions containing truncated light chains identified the predicted amphiphilic helix (residues 14-32) as sufficient to cause dimerization; cross-linking required a second helical segment (residues 33-46), Together the data presented suggest that two light chains interact to form a parallel dimeric structure, This arrangement has significant implications for the potential functions of this highly conserved molecule and suggests a mechanism by which it might dissociate nitric oxide synthase.