The yeast Coq4 polypeptide organizes a mitochondrial protein complex essential for coenzyme Q biosynthesis.
The yeast Coq4 polypeptide organizes a mitochondrial protein complex essential for coenzyme Q biosynthesis.
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DOI：
10.1016/j.bbalip.2008.10.006
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发表时间：
2009-01
影响因子：
4.8
通讯作者：
Clarke, Catherine F.
中科院分区：
文献类型：
--
作者：
Marbois, Betn;Gin, Peter;Gulmezian, Melissa;Clarke, Catherine F.
辅酶Q是有氧呼吸所必需的氧化还原活性脂质。辅酶q4多肽是Q在不可发酵碳源上的生物合成和生长所必需的，但其在这一途径中的确切功能尚不清楚。本文探讨了Coq4p在酵母Q生物合成多肽复合体中的功能作用。含有E226K取代的酵母菌coq4-1突变体不能在不可发酵的碳源上生长。coq4-1酵母突变体保留了显著的Coq3p o -甲基转移酶活性，并且从coq4-1和coq4-2 （E121K）酵母点突变体中分离的线粒体含有正常稳态水平的Coq多肽，而不像通常在Coq基因缺失的菌株中发现的Coq多肽水平降低。从酵母coq4点突变体中提取的洋地黄苷溶解线粒体提取物表明，Coq3p和coq4多肽不再作为高分子量复合物在一维和二维Blue - page上共迁移。同样，凝胶过滤层析证实，在coq4-1突变体线粒体中，o -甲基转移酶活性、Coq3p、Coq4p和Coq7p迁移被打乱。这些数据表明，Coq4p在组织Q生物合成所需的Coq酶复合体中起着重要作用。
Coenzyme Q is a redox active lipid essential for aerobic respiration. The Coq4 polypeptide is required for Q biosynthesis and growth on non-fermentable carbon sources, however its exact function in this pathway is not known. Here we probe the functional roles of Coq4p in a yeast Q biosynthetic polypeptide complex. A yeast coq4-1 mutant harboring an E226K substitution is unable to grow on nonfermentable carbon sources. The coq4-1 yeast mutant retains significant Coq3p O-methyltransferase activity, and mitochondria isolated from coq4-1 and coq4-2 (E121K) yeast point mutants contain normal steady state levels of Coq polypeptides, unlike the decreased levels of Coq polypeptides generally found in strains harboring coq gene deletions. Digitonin-solubilized mitochondrial extracts prepared from yeast coq4 point mutants show that Coq3p and Coq4 polypeptides no longer co-migrate as high molecular mass complexes by one- and two-dimensional Blue Native-PAGE. Similarly, gel filtration chromatography confirms that O-methyltransferase activity, Coq3p, Coq4p, and Coq7p migration are disorganized in the coq4-1 mutant mitochondria. The data suggest that Coq4p plays an essential role in organizing a Coq enzyme complex required for Q biosynthesis.
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影响因子：
2.7
作者：
Akada, R;Murakane, T;Nishizawa, Y
通讯作者：
Nishizawa, Y
DOI：
10.1016/s1388-1981(00)00019-6
发表时间：
2000-04-12
影响因子：
4.8
作者：
Hsu, AY;Do, TQ;Clarke, CF
通讯作者：
Clarke, CF
影响因子：
3.3
作者：
Bhagavan, HN;Chopra, RK
通讯作者：
Chopra, RK
DOI：
10.1073/pnas.0500929102
发表时间：
2005-03-22
影响因子：
11.1
作者：
Kickhoefer, VA;Garcia, Y;Rome, LH
通讯作者：
Rome, LH
影响因子：
3.2
作者：
HUGHES, PE;TOVE, SB
通讯作者：
TOVE, SB