The glycolytic enzyme enolase is present in sperm tail and displays nucleotide-dependent association with microtubules
The glycolytic enzyme enolase is present in sperm tail and displays nucleotide-dependent association with microtubules
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DOI：
10.1078/s0171-9335(04)70012-6
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发表时间：
2000-02-01
影响因子：
6.6
通讯作者：
Sentry, JW
中科院分区：
文献类型：
--
作者：
Gitlits, VM;Toh, BH;Sentry, JW
我们检测了烯醇化酶（2-磷酸- d -甘油水解酶）在分化大鼠生精细胞中的表达和定位。我们发现烯醇化酶在成熟精子和从细长精子分离的残余细胞质体中最丰富，而在减数分裂的初级精子细胞和圆形精子中几乎没有检测到烯醇化酶。我们通过免疫印迹法和免疫荧光法将烯醇化酶定位在成熟精子的尾部，分化生精细胞的RT-PCR分析仅检测到烯醇化酶的α亚型。由于已知几种糖酵解酶与脑制备的微管相关，我们研究了烯醇化酶与脑和睾丸微管的关联。我们发现，只有一小部分睾丸和脑源性胞质烯醇化酶（分别为4.9%和11.2%）与微管在紫杉醇存在下稳定沉积。在某些核苷酸过量（3mm ATP、CTP、GTP和ITP）的情况下，烯醇化酶与微管的关联被破坏，然而，UTP并非如此。这一观察结果与在0.5 mM AMP-PNP （ATP的不可水解类似物）存在下的发现一致，烯醇化酶与微管的关联增加。我们提出烯醇化酶与微管的核苷酸依赖性关联通过将能量生产与利用联系起来来调节酶活性。
We examined the expression and localisation of enolase (2-phospho-D-glycerate hydrolase) in differentiating rat spermatogenic cells. We found that enolase is most abundant in mature spermatozoa and in residual cytoplasmic bodies detached from elongating spermatids with little to no enolase detected in meiotic primary spermatocytes and round spermatids. We localised enolase mostly to the tail of mature spermatozoa by immunoblotting and by immunofluorescence, RT-PCR analysis of differentiating spermatogenic cells detected only the alpha isoform of enolase. As several glycolytic enzymes are known to associate with microtubules prepared from brain, we investigated the association of enolase with brain and testis microtubules. We found that only a small fraction of testis and brain-derived cytosolic enolase (4.9% and 11.2%, respectively) co-sediments with microtubules stabilised in the presence of taxol. In the presence of certain nucleotides in excess (3 mM ATP, CTP, GTP and ITP) the association of enolase with microtubules was disrupted, however, this was not the case for UTP. This observation is consistent with the finding that in the presence of 0.5 mM AMP-PNP, a nonhydrolysable analogue of ATP, there is an increased association of enolase with microtubules. We propose that the nucleotide-dependent association of enolase with microtubules regulates enzyme activity by linking energy production to utilisation.