Troponin T is capable of binding dystrophin via a leucine zipper.
Using genetic and physical assays for protein-protein interactions, we identified a fast isoform of troponin T that binds to dystrophin. Troponin T specifically bound to the first of two highly conserved leucine zipper motifs in the carboxy terminus of dystrophin [1,2]. Single amino acid changes in the zipper predicted to disrupt alpha-helix formation or cause steric hindrance abolished this binding. These data support the hypothesis that dystrophin couples the contractile apparatus to the sarcolemma and indicate that leucine zipper mediated protein-protein interactions are functionally important in the cytoskeleton as well as the nucleus.
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
J A
JA
Pearlman
P A
PA
Powaser
S J
SJ
Elledge
C T
CT
Caskey
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015139:Blotting, Southern; D017124:Conserved Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins; D016189:Dystrophin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D016350:Leucine Zippers; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014336:Troponin / Q000737:chemistry / Q000378:metabolism*; D020107:Troponin T; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; D016189:Dystrophin; D005656:Fungal Proteins; C052130:GAL4 protein, S cerevisiae; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D014336:Troponin; D020107:Troponin T; D004247:DNA; D001616:beta-Galactosidase