ASSEMBLY PROPERTIES OF DOMINANT AND RECESSIVE MUTATIONS IN THE SMALL MOUSE NEUROFILAMENT (NF-L) SUBUNIT
ASSEMBLY PROPERTIES OF DOMINANT AND RECESSIVE MUTATIONS IN THE SMALL MOUSE NEUROFILAMENT (NF-L) SUBUNIT
复制标题
DOI：
10.1083/jcb.111.5.2005
复制
发表时间：
1990-11-01
影响因子：
7.8
通讯作者：
CLEVELAND, DW
中科院分区：
文献类型：
--
作者：
GILL, SR;WONG, PC;CLEVELAND, DW
我们已经产生了一组的氨基和羧基末端缺失的NF-L神经丝基因，并确定了组装后的波形蛋白或野生型NF-L共表达的编码亚基的属性。缺失> 30%（头部的31个氨基酸）或90%（尾部的128个氨基酸）的NF-L分子不能并入中间丝网络中。杆状结构域中的羧基末端缺失产生显性突变体，其破坏由野生型亚基组装的阵列，甚至当以野生型亚基的约2%的水平存在时。当积累超过野生型亚基的约10%时，甚至保留55%尾部（61个氨基酸）的突变体也破坏正常阵列。由于> 90%的头部结构域的缺失产生不影响野生型细丝阵列的“隐性”组装缺陷亚基，而较小的缺失产生有效的网络破坏，我们得出结论，头部结构域中的一些序列（在残基31-87内）是细丝组装中最早步骤所需的。插入突变的非螺旋间隔区与杆结构域内显示，多达8个额外的氨基酸可以容忍，而不破坏装配能力。
We have generated a set of amino- and carboxy-terminal deletions of the NF-L neurofilament gene and determined the assembly properties of the encoded subunits after coexpression with vimentin or wild-type NF-L. NF-L molecules missing > 30% (31 amino acids of the head) or 90% (128 amino acids of the tail) failed to incorporate into intermediate filament networks. Carboxy-terminal deletions into the rod domain yield dominant mutants that disrupt arrays assembled from wild-type subunits, even when present at leves of .apprxeq.2% of the wild-type subunits. Even mutants retaining 55% of the tail (61 amino acids) disrupt normal arrays when accumulated above .apprxeq.10% of wild-type subunits. Since deletion of > 90% of the head domain produces "recessive" assembly incompetent subunits that do not affect wild-type filament arrays, whereas smaller deletions yield efficient network disruption, we conclude that some sequence(s) in the head domain (within residues 31-87) are required for the earliest steps in filament assembly. Insertional mutagenesis in the nonhelical spacer region within with rod domain reveals that as many as eight additional amino acids can be tolerated without disrupting assembly competence.