Phosphofructokinase muscle-specific isoform requires caveolin-3 expression for plasma membrane recruitment and caveolar targeting: implications for the pathogenesis of caveolin-related muscle diseases.
Previous co-immunoprecipitation studies have shown that endogenous PFK-M (phosphofructokinase, muscle-specific isoform) associates with caveolin (Cav)-3 under certain metabolic conditions. However, it remains unknown whether Cav-3 expression is required for the plasma membrane recruitment and caveolar targeting of PFK-M. Here, we demonstrate that recombinant expression of Cav-3 dramatically affects the subcellular localization of PFK-M, by targeting PFK-M to the plasma membrane, and by trans-locating PFK-M to caveolae-enriched membrane domains. In addition, we show that the membrane recruitment and caveolar targeting of PFK-M appears to be strictly dependent on the concentration of extracellular glucose. Interestingly, recombinant expression of PFK-M with three Cav-3 mutants [DeltaTFT (63 to 65), P104L, and R26Q], which harbor the same mutations as seen in the human patients with Cav-3-related muscle diseases, causes a substantial reduction in PFK-M expression levels, and impedes the membrane recruitment of PFK-M. Analysis of skeletal muscle tissue samples from Cav-3(-/-) mice directly demonstrates that Cav-3 expression regulates the phenotypic behavior of PFK-M. More specifically, in Cav-3-null mice, PFK-M is no longer targeted to the plasma membrane, and is excluded from caveolar membrane domains. As such, our current results may be important in understanding the pathogenesis of Cav-3-related muscle diseases, such as limb-girdle muscular dystrophy-1C, distal myopathy, and rippling muscle disease, that are caused by mutations within the human Cav-3 gene.
Sotgia
Federica
F
Departments of Molecular Pharmacology and Cell Biology, and The Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Bonuccelli
Gloria
G
Minetti
Carlo
C
Woodman
Scott E
SE
Capozza
Franco
F
Kemp
Robert G
RG
Scherer
Philipp E
PE
Lisanti
Michael P
MP
D000818:Animals; D019556:COS Cells; D021941:Caveolae / Q000378:metabolism*; D051242:Caveolin 1; D051244:Caveolin 3; D022461:Caveolins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D045604:Extracellular Fluid / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism*; D009135:Muscular Diseases / Q000209:etiology; D009154:Mutation / Q000502:physiology; D010641:Phenotype; D025221:Phosphofructokinases / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D014018:Tissue Distribution / Q000502:physiology
C495541:Cav1 protein, mouse; C495548:Cav3 protein, mouse; D051242:Caveolin 1; D051244:Caveolin 3; D022461:Caveolins; D007527:Isoenzymes; D011994:Recombinant Proteins; D025221:Phosphofructokinases; D005947:Glucose