Expression of caveolin-1 in lymphocytes induces caveolae formation and recruitment of phosphofructokinase to the plasma membrane.
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.
Vallejo
Johana
J
Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO 65212, USA.
Hardin
Christopher D
CD
D021941:Caveolae / Q000648:ultrastructure*; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology*; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism* / Q000648:ultrastructure; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D025221:Phosphofructokinases / Q000032:analysis / Q000378:metabolism*; D014162:Transfection
D018076:DNA, Complementary; D025221:Phosphofructokinases