Fimbrin is a homologue of the cytoplasmic phosphoprotein plastin and has domains homologous with calmodulin and actin gelation proteins.

Abstract

Abstract. Fimbrin is an actin-bundling protein found in intestinal microvilli, hair cell stereocilia, and fibroblast filopodia. The complete protein sequence (630 residues) of chicken intestine fimbrin has been determined from two full-length cDNA clones. The sequence encodes a small amino-terminal domain (115 residues) that is homologous with two calcium-binding sites of calmodulin and a large carboxy-terminal domain (500 residues) consisting of a fourfold-repeated 125-residue sequence. This repeat is homologous with the actin-binding domain of alpha-actinin and the amino-terminal domains of dystrophin, actin-gelation protein, and beta-spectrin. The presence of this duplicated domain in fimbrin links actin bundling proteins and gelation proteins into a common family of actin cross-linking proteins. Fimbrin is also homologous in sequence with human L-plastin and T-plastin. L-plastin is found in only normal or transformed leukocytes where it becomes phosphorylated in response to IL 1 or phorbol myristate acetate. T-plastin is found in cells of solid tissues where it does not become phosphorylated. Neoplastic cells derived from solid tissues express both isoforms. The differences in expression, sequence, and phosphorylation suggest possible functional differences between fimbrin isoforms.

Interaction of a Dictyostelium member of the plastin/fimbrin family with actin filaments and actin-myosin complexes.

“…The first fimbrin was identified as a major component of the microvilli in the intestinal brush border (Bretscher and Weber, 1980;Bretscher, 1981;Glenney et al, 1981). The sequence of chicken fimbrin (de Arruda et al, 1990) shows a high degree of homology to human L-plastin, a protein phosphorylated in response to growth factors interleukin 1 and interleukin 2 and to phorbol esters (Goldstein et al, 1985;Matsushima et al, 1988). In addition to L-plastin, two isoforms, Tplastin and I-plastin, have been identified in man (Lin et al, 1988(Lin et al, , 1994.…”

cDNA Clones Encoding 1,3-β-Glucanase and a Fimbrin-Like Cytoskeletal Protein Are Induced by Al Toxicity in Wheat Roots

“…The wheat fimbrin-like amino acid sequence aligned from residues 182 of human plastins and chicken fimbrin and from 205 of yeast (Sac6p) fimbrin, suggesting that the partial wheat cDNA clone is missing approximately 182 to 205 amino acids from the N-terminal region. Like other fimbrin proteins, the putative wheat fimbrin-like protein possesses the two 27-amino acid domains that are very similar to actin-binding domains identified in other proteins such as chicken fimbrin (de Arruda et al, 1990), a-actinin (Blanchard et al, 1989), and I-and T-plastin (Lin et al, www.plantphysiol.org on May 11, 2018 -Published by Downloaded from Copyright © 1997 American Society of Plant Biologists. All rights reserved.…”

“…The nucleotide sequence exhibits 50% similarity with human I-plastin (Lin et al, 1994), T-plastin (Lin et al, 1993), and L-plastin (Lin and Leavitt, 1988), with slime mold (Dyctiostelium discoideum) fimbrin (J. Prassler, unpublished data; accession no. L36202), with the bakers' yeast (Saccharomyces cerevisiae) SAC6 gene encoding fimbrin (Adams et al, 1991), and with chicken (Callus gallus) fimbrin (de Arruda et al, 1990). These proteins all belong to a group of actin cross-linking proteins that bundle actin filaments in vitro (Adams et al, 1991).…”

“…The wheat sequence was found to be 43% identical to Sac6p or fimbrin from bakers' yeast (Adams et al, 1991) and 41% identical to L-, T-, I-plastin (Lin and Leavitt, 1988;Lin et al, 1993Lin et al, , 1994, chicken fimbrin (de Arruda et al, 1990), and slime mold fimbrin (J. Prassler, unpublished data). The deduced amino acid sequence was aligned with other fimbrin amino acid sequences from I-, L-, and T-plastin from humans, slime mold, yeast, and chicken (Fig.…”

“…All rights reserved. (Lin and Leavitt, 1 988;Lin et al, 1993Lin et al, , 1994, D. discoideum (Dd, L36202) (J. Prassler, unpublished data), 5. cerevisiae (Sc, X63867, X63918) (Adams et al, 1991), and C. gallus (Gg, X52562) (de Arruda et al, 1990) were aligned to the partial predicted amino acid sequence of a fimbrin-like protein of T. aestivum (Ta). Gaps to optimize alignments are designated by dashes (-).…”