Lack of developmental redundancy between Unc45 proteins in zebrafish muscle development.
Lack of developmental redundancy between Unc45 proteins in zebrafish muscle development.
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DOI：
10.1371/journal.pone.0048861
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Pilgrim D
中科院分区：
文献类型：
--
作者：
Comyn SA;Pilgrim D
由于脊椎动物中大多数蛋白质编码基因具有基因组内同源物，因此很难从突变表型分析中消除功能冗余的可能性，无论是由遗传损伤还是短暂敲除产生的。进一步使这些分析复杂化的是，并不是所有的基因产物都具有可以在体外检测的活性，在体外，各种家族成员的效率可以与恒定的底物进行比较。两种脊椎动物UNC-45同源物unc45a和unc45b在细胞培养中被敲除时影响不同的肌肉分化阶段，并且在体外具有功能冗余。UNC-45蛋白是UCS （UNC-45/CRO1/She4p）蛋白家族的成员，已被证明通过与肌球蛋白运动结构域的直接相互作用来调节从真菌到脊椎动物的肌球蛋白依赖功能。为了验证这些unc45同源基因在体内是否存在相同的功能关系，我们检测了双纯合unc45b−/−的发育表型；Unc45a−/−突变斑马鱼胚胎。我们特别关注了由于合子缺乏这两种同源物而对形态和基因表达的综合影响。我们发现unc45b−/−和unc45b−/−；un45a−/−胚胎在表型上难以区分，两个突变体表现出相同的心脏、骨骼肌和颌骨缺陷。我们也没有发现任何证据支持合子Unc45a功能在成肌细胞分化中的作用。与之前的体外研究相反，这排除了体内Unc45a和Unc45b之间功能冗余的模型。相反，我们的系统发育和表型分析为UCS蛋白家族进化中功能分化的作用提供了证据。
Since the majority of protein-coding genes in vertebrates have intra-genomic homologues, it has been difficult to eliminate the potential of functional redundancy from analyses of mutant phenotypes, whether produced by genetic lesion or transient knockdown. Further complicating these analyses, not all gene products have activities that can be assayed in vitro, where the efficiency of the various family members can be compared against constant substrates. Two vertebrate UNC-45 homologues, unc45a and unc45b, affect distinct stages of muscle differentiation when knocked down in cell culture and are functionally redundant in vitro. UNC-45 proteins are members of the UCS (UNC-45/CRO1/She4p) protein family that has been shown to regulate myosin-dependent functions from fungi to vertebrates through direct interaction with the myosin motor domain. To test whether the same functional relationship exists between these unc45 paralogs in vivo, we examined the developmental phenotypes of doubly homozygous unc45b−/−; unc45a−/− mutant zebrafish embryos. We focused specifically on the combined effects on morphology and gene expression resulting from the zygotic lack of both paralogs. We found that unc45b−/− and unc45b−/−; unc45a−/− embryos were phenotypically indistinguishable with both mutants displaying identical cardiac, skeletal muscle, and jaw defects. We also found no evidence to support a role for zygotic Unc45a function in myoblast differentiation. In contrast to previous in vitro work, this rules out a model of functional redundancy between Unc45a and Unc45b in vivo. Instead, our phylogenetic and phenotypic analyses provide evidence for the role of functional divergence in the evolution of the UCS protein family.
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DOI：
10.1073/pnas.0707330105
发表时间：
2008-01-15
影响因子：
11.1
作者：
Du, Shao Jun;Li, Huiqing;Zhong, Yongwang
通讯作者：
Zhong, Yongwang
影响因子：
4
作者：
Just, Steffen;Meder, Benjamin;Rottbauer, Wolfgang
通讯作者：
Rottbauer, Wolfgang
影响因子：
4
作者：
Lee, Chi F.;Melkani, Girish C.;Bernstein, Sanford I.
通讯作者：
Bernstein, Sanford I.
影响因子：
2.7
作者：
French, Curtis R.;Erickson, Timothy;Waskiewicz, Andrew J.
通讯作者：
Waskiewicz, Andrew J.
影响因子：
2.5
作者：
KIMMEL, CB;BALLARD, WW;SCHILLING, TF
通讯作者：
SCHILLING, TF