Chlamydomonas inner-arm dynein mutant, ida5, has a mutation in an actin-encoding gene.
Chlamydomonas inner-arm dynein mutant, ida5, has a mutation in an actin-encoding gene.
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DOI：
10.1083/jcb.137.3.649
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发表时间：
1997-05-05
影响因子：
7.8
通讯作者：
Kamiya, R
中科院分区：
文献类型：
--
作者：
KatoMinoura, T;Hirono, M;Kamiya, R
鞭毛衣单胞菌内臂动力蛋白由7个亚种（a-g）组成，其中除f外均含有肌动蛋白作为亚基。突变体ida5和新菌株ida5-t缺少4个亚种（a、c、d和e）。这些突变体被发现在常规的肌动蛋白基因中有突变，使得其产物完全丢失；Ida5有一个单碱基缺失，导致一个停止密码子位于编码区5 '端约三分之二的位置，并且Ida5 -t缺乏整个肌动蛋白基因的很大一部分。ida5轴突组和内臂亚种b和g的二维凝胶电泳图谱缺少肌动蛋白斑点（等电点[pI] = ~ 5.3），但有两个新的斑点，pI分别为~ 5.6和~ 5.7。用不同种类的抗肌动蛋白抗体进行Western blot检测表明，这两个新斑点的蛋白与常规肌动蛋白不同，但具有一定的抗原性。由于衣藻已被证明只有一个常规肌动蛋白基因的拷贝，ida5和ida5-t中的新斑点很可能来自另一个基因，该基因编码一种新的肌动蛋白样蛋白（NAP），迄今为止尚未在野生型细胞中检测到。除了f外，这些突变体还保留了两个内臂亚种b和g，可能是因为NAP可以在这些亚种中替代肌动蛋白，而在其他亚种中则不能。ida5和ida5-t细胞的净生长速率与野生型没有差异，但交配效率大大降低。这种缺陷显然是由受精小管生长缺陷引起的。这些结果表明NAP可以执行细胞质中常规肌动蛋白的部分功能，但不是全部功能，并提出了衣藻可以在没有普通肌动蛋白的情况下生存的可能性。
Chlamydomonas flagellar inner-arm dynein consists of seven subspecies (a–g), of which all but f contain actin as subunits. The mutant ida5 and a new strain, ida5-t, lack four subspecies (a, c, d, and e). These mutants were found to have mutations in the conventional actin gene, such that its product is totally lost; ida5 has a single-base deletion that results in a stop codon at a position about two-thirds from the 5′ end of the coding region, and ida5-t lacks a large portion of the entire actin gene. Two-dimensional gel electrophoresis patterns of the axonemes and inner-arm subspecies b and g of ida5 lacked the spot of actin (isoelectric point [pI] = ∼5.3) but had two novel spots with pIs of ∼5.6 and ∼5.7 instead. Western blot with different kinds of anti-actin antibodies suggested that the proteins responsible for the two novel spots and conventional actin are different but share some antigenicity. Since Chlamydomonas has been shown to have only a single copy of the conventional actin gene, it is likely that the novel spots in ida5 and ida5-t originated from another gene(s) that codes for a novel actin-like protein(s) (NAP), which has hitherto been undetected in wildtype cells. These mutants retain the two inner-arm subspecies b and g, in addition to f, possibly because NAP can functionally substitute for the actin in these subspecies while they cannot in other subspecies. The net growth rate of ida5 and ida5-t cells did not differ from that of wild type, but the mating efficiency was greatly reduced. This defect was apparently caused by deficient growth of the fertilization tubule. These results suggest that NAP can carry out some, but not all, functions performed by conventional actin in the cytoplasm and raise the possibility that Chlamydomonas can live without ordinary actin.
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影响因子：
3.3
作者：
LEDIZET, M;PIPERNO, G
通讯作者：
PIPERNO, G
DOI：
10.1073/pnas.74.8.3456
发表时间：
1977-01-01
影响因子：
11.1
作者：
LUCK, D;PIPERNO, G;HUANG, B
通讯作者：
HUANG, B
影响因子：
5.6
作者：
MINTY, AJ;ALONSO, S;BUCKINGHAM, ME
通讯作者：
BUCKINGHAM, ME
影响因子：
3.5
作者：
MUTO, E;EDAMATSU, M;KAMIYA, R
通讯作者：
KAMIYA, R
影响因子：
2.9
作者：
CHOMCZYNSKI, P;SACCHI, N
通讯作者：
SACCHI, N