ATP production in Chlamydomonas reinhardtii flagella by glycolytic enzymes
ATP production in Chlamydomonas reinhardtii flagella by glycolytic enzymes
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DOI：
10.1091/mbc.e05-04-0347
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发表时间：
2005-10-01
影响因子：
3.3
通讯作者：
Mitchell, DR
中科院分区：
文献类型：
--
作者：
Mitchell, BF;Pedersen, LB;Mitchell, DR
真核生物的纤毛和鞭毛是细长的细胞器，细胞质的扩散可能无法支持动力蛋白马达活动所需的高ATP浓度。我们在莱茵衣藻鞭毛中发现了催化糖酵解下半部分三个步骤（磷酸甘油酸变位酶、烯醇化酶和丙酮酸激酶）的酶活性。这些酶每消耗一个底物分子就能产生一个ATP分子。鞭毛分级分离显示烯醇化酶至少部分与轴丝相关，而磷酸甘油酸变位酶和丙酮酸激酶主要存在于可溶于去垢剂的（膜 + 基质）组分中。我们进一步表明，轴丝烯醇化酶是CPC1中央对复合物的一个亚基，并且cpc1突变体中鞭毛烯醇化酶水平的降低与先前在cpc1菌株中报道的鞭毛ATP浓度降低和体内摆动频率降低相关。我们得出结论，整个鞭毛区室的原位ATP合成对于正常的鞭毛运动是必不可少的。
Eukaryotic cilia and flagella are long, thin organelles, and diffusion from the cytoplasm may not be able to support the high ATP concentrations needed for dynein motor activity. We discovered enzyme activities in the Chlamydomonas reinhardtii flagellum that catalyze three steps of the lower half of glycolysis (phosphoglycerate mutase, enolase, and pyruvate kinase). These enzymes can generate one ATP molecule for every substrate molecule consumed. Flagellar fractionation shows that enolase is at least partially associated with the axoneme, whereas phosphoglycerate mutase and pyruvate kinase primarily reside in the detergent-soluble (membrane + matrix) compartments. We further show that axonemal enolase is a subunit of the CPC1 central pair complex and that reduced flagellar enolase levels in the cpc1 mutant correlate with the reduced flagellar ATP concentrations and reduced in vivo beat frequencies reported previously in the cpc1 strain. We conclude that in situ ATP synthesis throughout the flagellar compartment is essential for normal flagellar motility.