The F-actin capping proteins of Physarum polycephalum: cap42(a) is very similar, if not identical, to fragmin and is structurally and functionally very homologous to gelsolin; cap42(b) is Physarum actin.
We have carried out a primary structure analysis of the F-actin capping proteins of Physarum polycephalum. Cap42(b) was completely sequenced and was found to be identical with Physarum actin. Approximately 88% of the sequence of cap42(a) was determined. Cap42(a) and fragmin were found to be identical by amino acid composition, isoelectric point, mol. wt, elution time on reversed-phase chromatography and amino acid sequence of their tryptic peptides. The available sequence of cap42(a) is greater than 36% homologous with the NH2-terminal 42-kd domain of human gelsolin. A highly homologous region of 16 amino acids is also shared between cap42(a), gelsolin and the Acanthamoeba profilins. Cap42(a) binds two actin molecules in a similar way to gelsolin suggesting a mechanism of F-actin modulation that has been conserved during evolution.
Ampe
C
C
Laboratorium voor Genetica, Rijksuniversiteit Gent, Belgium.
Vandekerckhove
J
J
D051339:Actin Depolymerizing Factors; D000199:Actins / Q000235:genetics*; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics*; D051345:Destrin; D018260:Gelsolin; D006495:Heparin, Low-Molecular-Weight / Q000235:genetics; D006801:Humans; D008840:Microfilament Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis; D010804:Physarum / Q000235:genetics*; D013329:Structure-Activity Relationship
D051339:Actin Depolymerizing Factors; D000199:Actins; D000596:Amino Acids; D002135:Calcium-Binding Proteins; D051345:Destrin; D018260:Gelsolin; D006495:Heparin, Low-Molecular-Weight; D008840:Microfilament Proteins; D010446:Peptide Fragments