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Mutation of the Caveolin‐Scaffolding Domain Reduces Phosphofructokinase Localization to the Plasma Membrane in Vascular Smooth Muscle
Author(s) -
Hernandez Mark J.,
Hardin Christopher D.
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.965.1
Subject(s) - caveolin 3 , caveolae , mutant , microbiology and biotechnology , caveolin , chemistry , mutagenesis , gene isoform , biochemistry , amino acid , dysferlin , biology , membrane , gene
We have previously demonstrated the role of caveolin‐1(CAV‐1) as a scaffold to localize glycolytic enzymes to the plasma membrane. Because the caveolin scaffolding domain (CSD) has been implicated in the interaction of caveolins with proteins that reside in the caveolae we sought to investigate the role of the CSD in targeting PFK in smooth muscle. We disrupted the CSD's ability to target PFK by site directed mutagenesis of a single residue without altering the membrane localization of the mutant CAV‐1. Using in vitro site directed mutagenesis we mutated aromatic amino acid phenylalanine F92, a highly conserved residue found in all three caveolins isoforms that is essential for interaction in vivo, to amino acid residue glycine. We previously reported CAV‐1 overexpression resulted in the targeting of PFK to the membrane. Here we report that only 34.3 % of PFK localized with CAV‐1 after overexpression of mutant CAV‐1, in contrast to 69.2 % of PFK which localized with CAV‐1 after overexpression of wild type CAV‐1. These results show CAV‐1 membrane distribution without targeting PFK to the membrane after transfection of mutant CAV‐1. We propose that an interaction of CAV‐1 with PFK exists through interaction of the CSD with a binding motif in PFK. Support by NIH DK 60668.