Expression of caveolin‐1 in lymphocytes induces caveolae formation and recruitment of phosphofructokinase to the plasma membrane
Expression of caveolin‐1 in lymphocytes induces caveolae formation and recruitment of phosphofructokinase to the plasma membrane
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DOI：
10.1096/fj.04-2380fje
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发表时间：
2005-04
期刊：
影响因子：
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通讯作者：
J. Vallejo;C. Hardin
中科院分区：
文献类型：
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作者：
J. Vallejo;C. Hardin
碳水化合物代谢的区间化已在广泛的组织中被显示，包括与细胞质膜相关的糖酵解的一个区室的报道。然而，只有在红细胞中，质膜相关的糖酵解途径才有建立的物理基础。我们先前已经发现，磷酸果糖激酶(PFK)似乎与相当普遍的质膜蛋白小窝蛋白-1(CAV-1)共定位，这与CAV-1作为糖酵解到质膜的锚的作用一致。为了验证CAV-1作为PFK支架蛋白的假设，我们将人CAV-1基因导入人淋巴细胞(不表达CAV-1的细胞)。我们证明，CAV-1在淋巴细胞中的表达导致质膜上形成小凹，并通过将PFK募集到质膜上来影响PFK的亚细胞定位。CAV-1对pFK的靶向也被证实，两个荧光团之间的相关性为0.97±0.004。这一发现具有重要意义，因为它说明了CAV-1在质膜上产生糖酵解酶结合位点的可行性。因此，我们得出结论，CAV-1作为PFK的支架蛋白发挥作用，这可能有助于阐明多种细胞类型中碳水化合物向质膜划分的基础。
Compartmentation of carbohydrate metabolism has been shown in a wide range of tissues including reports of one compartment of glycolysis associated with the plasma membrane of cells. However, only in the erythrocyte has the physical basis for plasma membrane‐associated glycolytic pathway been established. We have previously found that phosphofructokinase (PFK) appeared to colocalize with the fairly ubiquitous plasma membrane protein caveolin‐1 (CAV‐1), consistent with a role for CAV‐1 as an anchor for glycolysis to the plasma membrane. To test the hypothesis that CAV‐1 functions as a scaffolding protein for PFK, we transfected human lymphocytes (a cell without CAV‐1 expression) with human CAV‐1 cDNA. We demonstrate that expression of CAV‐1 in lymphocytes results in the formation of caveolae at the plasma membrane and affects the subcellular localization of PFK by recruiting PFK to the plasma membrane. Targeting of PFK by CAV‐1 also was validated by the significant colocalization between the proteins after transfection, which resulted in a correlation of 0.97 ± 0.004 between the two fluorophores. This finding is significant in as much as it illustrates the CAV‐1 feasibility of generating binding sites for glycolytic enzymes on the plasma membrane. We therefore conclude that CAV‐1 functions as a scaffolding protein for PFK and that this may contribute to the elucidation of the basis for carbohydrate compartmentation to the plasma membrane in a wide variety of cell types.