Oligomerization of mouse alpha 1-syntrophin and self-association of its pleckstrin homology domain 1 containing sequences.
Syntrophins are known to self-associate to form oligomers. Mouse alpha 1-syntrophin sequences were produced as chimeric fusion proteins in bacteria and were found to also oligomerize and in a micromolar Ca(2+)-dependent manner. The oligomerization was localized to the N-terminal pleckstrin homology domain (PH1) or adjacent sequences; the second, C-terminal PH2 domain did not show oligomerization. PH1 was found to self-associate, and calmodulin or Ca(2+)-chelating agents such as ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) could effectively prevent this oligomerization. A single calmodulin bound per syntrophin to cause inhibition of the precipitation. Since calmodulin inhibited syntrophin oligomerization in the presence or absence of Ca(2+), Ca(2+) binding to syntrophin is responsible for the inhibition by EGTA of syntrophin oligomerization.
Department of Biochemistry, 858 Madison Avenue, University of Tennessee, Memphis, Tennessee 38163, USA.
S A
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Oak
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Jarrett
D000818:Animals; D001798:Blood Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002417:Cattle; D002498:Centrifugation; D011232:Chemical Precipitation; D003956:Dialysis; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D009124:Muscle Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D001798:Blood Proteins; D002135:Calcium-Binding Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; C039077:platelet protein P47; C091825:syntrophin alpha1; D002118:Calcium