| 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 . ^^^ 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 . ^^^ |