Cingulin interacts with F-actin in vitro.
Cingulin, a M(r) 140-160 kDa protein of the cytoplasmic plaque of epithelial tight junctions (TJ), interacts in vitro with TJ proteins and myosin. Here we investigated cingulin interaction with actin, using His-tagged, full-length Xenopus laevis cingulin expressed in insect cells, and glutathione S-transferase (GST) fusion proteins of fragments of cingulin expressed in bacteria. Purified full-length cingulin co-pelleted with F-actin after high speed centrifugation, and promoted the sedimentation of F-actin under low speed centrifugation, suggesting that cingulin is an actin-cross-linking protein. The actin interaction of GST fusion proteins containing fragments of Xenopus cingulin suggested that the F-actin binding site is between residues 101 and 294.
D'Atri
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Department of Molecular Biology, University of Geneva, Geneva 4, Switzerland.
Citi
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D000199:Actins / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D003432:Cross-Linking Reagents; D003599:Cytoskeleton / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008840:Microfilament Proteins; D010449:Peptide Mapping; D011485:Protein Binding; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera; D019108:Tight Junctions / Q000737:chemistry / Q000378:metabolism; D029867:Xenopus Proteins; D014982:Xenopus laevis
D000199:Actins; C489228:CGN protein, Xenopus; C061407:CGN protein, human; D003432:Cross-Linking Reagents; D008565:Membrane Proteins; D008840:Microfilament Proteins; D011993:Recombinant Fusion Proteins; D029867:Xenopus Proteins