The Exoskeleton Collagens in Caenorhabditis elegans Are Modified by Prolyl 4-Hydroxylases with Unique Combinations of Subunits*
The Exoskeleton Collagens in Caenorhabditis elegans Are Modified by Prolyl 4-Hydroxylases with Unique Combinations of Subunits*
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秀丽隐杆线虫的外骨骼胶原蛋白由脯氨酰 4-羟化酶与独特的亚基组合进行修饰*
DOI：
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发表时间：
2002
影响因子：
4.8
通讯作者：
A. P. Page
中科院分区：
文献类型：
--
作者：
J. Myllyharju;L. Kukkola;A. Winter;A. P. Page
胶原蛋白脯氨酰4-羟化酶（P4 Hs，EC1.14.11.2）在细胞外基质的合成中起关键作用。在脊椎动物和果蝇中发现的酶是α2β2四聚体，其中蛋白质二硫键异构酶（PDI）是β亚基。在秀丽隐杆线虫中鉴定出两种保守的α亚基异构体，PHY-1和PHY-2。本文报道了在重组表达系统中和体内由这些多肽和单个β亚基PDI-2组装的三种独特的P4 H形式，即PHY-1/PHY-2/（PDI-2）2混合四聚体和PHY-1/PDI-2和PHY-2/PDI-2二聚体。混合四聚体是野生型C中主要的P4 H形式。线虫butphy-2−/− andphy-1−/−（dpy-18）突变体线虫可以通过分别增加PHY-1/PDI-2和PHY-2/PDI-2二聚体的组装来补偿其缺失。所有三种混合四聚体形成多肽PHY-1、PHY-2和PDI-2在合成表皮胶原的下皮细胞中共表达。混合四聚体的催化性质与其他P4 H的催化性质相似，并且发现2-酮戊二酸的类似物对P4 H突变株产生严重的温度依赖性影响。新的混合四聚体的形成是物种特异性的，并且对杂交重组PHY多肽的研究表明，PHY-1和PHY-2中的残基Gln 121-Ala 271和Asp 1-Leu 122分别对其组装至关重要。
The collagen prolyl 4-hydroxylases (P4Hs, EC1.14.11.2) play a critical role in the synthesis of the extracellular matrix. The enzymes characterized from vertebrates andDrosophila are α2β2 tetramers, in which protein disulfide isomerase (PDI) serves as the β subunit. Two conserved α subunit isoforms, PHY-1 and PHY-2, have been identified in Caenorhabditis elegans. We report here that three unique P4H forms are assembled from these polypeptides and the single β subunit PDI-2, both in a recombinant expression system andin vivo, namely a PHY-1/PHY-2/(PDI-2)2 mixed tetramer and PHY-1/PDI-2 and PHY-2/PDI-2 dimers. The mixed tetramer is the main P4H form in wild-type C. elegans butphy-2−/− andphy-1−/− (dpy-18) mutant nematodes can compensate for its absence by increasing the assembly of the PHY-1/PDI-2 and PHY-2/PDI-2 dimers, respectively. All three of the mixed tetramer-forming polypeptides PHY-1, PHY-2, and PDI-2 are coexpressed in the cuticle collagen-synthesizing hypodermal cells. The catalytic properties of the mixed tetramer are similar to those of other P4Hs, and analogues of 2-oxoglutarate were found to produce severe temperature-dependent effects on P4H mutant strains. Formation of the novel mixed tetramer was species-specific, and studies with hybrid recombinant PHY polypeptides showed that residues Gln121–Ala271 and Asp1–Leu122 in PHY-1 and PHY-2, respectively, are critical for its assembly.
影响因子：
3.5
作者：
Timmons, L;Court, DL;Fire, A
通讯作者：
Fire, A
影响因子：
2.7
作者：
PRIESS, JR;HIRSH, DI
通讯作者：
HIRSH, DI
DOI：
10.1073/pnas.97.9.4736
发表时间：
2000-04-25
影响因子：
11.1
作者：
Friedman, L;Higgin, JJ;Kimble, J
通讯作者：
Kimble, J