Identification of a nerve ending-enriched 29-kDa protein, labeled with [3-32P]1,3-bisphosphoglycerate, as monophosphoglycerate mutase: inhibition by fructose-2,6-bisphosphate via enhancement of dephosphorylation.
Identification of a nerve ending-enriched 29-kDa protein, labeled with [3-32P]1,3-bisphosphoglycerate, as monophosphoglycerate mutase: inhibition by fructose-2,6-bisphosphate via enhancement of dephosphorylation.
复制标题
鉴定富含神经末梢的 29-kDa 蛋白，用 [3-32P]1,3-二磷酸甘油酸标记，作为单磷酸甘油酸变位酶：通过增强去磷酸化来抑制果糖 2,6-二磷酸。
DOI：
10.1046/j.1471-4159.2003.01777.x
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发表时间：
2003
影响因子：
4.7
通讯作者：
Ueda,Tetsufumi
中科院分区：
文献类型：
--
作者：
Ikemoto,Atsushi;Ueda,Tetsufumi
葡萄糖代谢对于正常的大脑功能至关重要。有证据表明，糖酵解除了产生 ATP 外，在维持正常突触功能方面也发挥着重要作用。为了了解糖酵解中间体在突触功能中的潜在参与，我们制备了[3-32P]1,3-二磷酸甘油酸和[32P]3-磷酸甘油酸，并寻找它们与特定神经末梢蛋白的相互作用。我们发现 29-kDa 蛋白质是用 [3-32P]1,3-二磷酸甘油酸或 [32P]3-磷酸甘油酸标记的主要成分。该蛋白被鉴定为单磷酸甘油酸变位酶（PGAM）。这种标记在大脑和突触体胞质部分中非常高，这与糖酵解在突触功能中的重要性一致。有趣的是，果糖-2,6-二磷酸 (Fru-2,6-P2) 抑制 PGAM 磷酸化和酶活性。此外，Fru-2,6-P2 有效刺激 32P 标记的 PGAM 释放[32P]磷酸盐（EC50= 1 μm），表明 Fru-2,6-P2 明显降低 PGAM 磷酸化和酶活性可能是由于刺激 PGAM 去磷酸化。讨论了这些发现的意义。
Glucose metabolism is of vital importance in normal brain function. Evidence indicates that glycolysis, in addition to production of ATP, plays an important role in maintaining normal synaptic function. In an effort to understand the potential involvement of a glycolytic intermediate(s) in synaptic function, we have prepared [3‐32P]1,3‐bisphosphoglycerate and [32P]3‐phosphoglycerate and sought their interaction with a specific nerve‐ending protein. We have found that a 29‐kDa protein is the major component labeled with either [3‐32P]1,3‐bisphosphoglycerate or [32P]3‐phosphoglycerate. The protein was identified as monophosphoglycerate mutase (PGAM). This labeling was remarkably high in the brain and synaptosomal cytosol fraction, consistent with the importance of glycolysis in synaptic function. Of interest, fructose‐2,6‐bisphosphate (Fru‐2,6‐P2) inhibited PGAM phosphorylation and enzyme activity. Moreover, Fru‐2,6‐P2potently stimulated release of [32P]phosphate from the32P‐labeled PGAM (EC50= 1 µm), suggesting that apparent reduction of PGAM phosphorylation and enzyme activity by Fru‐2,6‐P2may be due to stimulation of dephosphorylation of PGAM. The significance of these findings is discussed.