Nucleation of actin polymerization from profilactin. Opposite effects of different nuclei.
The lag in polymerization of calf spleen profilactin in response to addition of MgCl2 can be overcome by small amounts of spectrin-actin-band 4.1 complex, covalently crosslinked actin oligomers or sonicated F-actin. All of these factors also nucleate polymerization of pure actin. Another nucleator of actin polymerization, villin, delays filaments formation from profilactin. A simple model of the interaction of profilin with actin can explain these apparently conflicting results in terms of the polarity with which actin filaments elongate from the different nuclei.
D000199:Actins / Q000378:metabolism*; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D003598:Cytoskeletal Proteins; D003599:Cytoskeleton / Q000378:metabolism*; D008274:Magnesium / Q000378:metabolism; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009479:Neuropeptides; D051304:Profilins; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D013049:Spectrin / Q000378:metabolism; D013154:Spleen
D000199:Actins; D001798:Blood Proteins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009479:Neuropeptides; D051304:Profilins; D011506:Proteins; C028841:erythrocyte membrane band 4.1 protein; C120557:erythrocyte membrane protein band 4.1-like 1; C024782:profilactin; C026615:villin; D013049:Spectrin; D008274:Magnesium