Structural and functional evaluation of C. elegans filamins FLN-1 and FLN-2

PLoS One. 2011;6(7):e22428. doi: 10.1371/journal.pone.0022428. Epub 2011 Jul 25.

Abstract

Filamins are long, flexible, multi-domain proteins composed of an N-terminal actin-binding domain (ABD) followed by multiple immunoglobulin-like repeats (IgFLN). They function to organize and maintain the actin cytoskeleton, to provide scaffolds for signaling components, and to act as mechanical force sensors. In this study, we used transcript sequencing and homology modeling to characterize the gene and protein structures of the C. elegans filamin orthologs fln-1 and fln-2. Our results reveal that C. elegans FLN-1 is well conserved at the sequence level to vertebrate filamins, particularly in the ABD and several key IgFLN repeats. Both FLN-1 and the more divergent FLN-2 colocalize with actin in vivo. FLN-2 is poorly conserved, with at least 23 IgFLN repeats interrupted by large regions that appear to be nematode-specific. Our results indicate that many of the key features of vertebrate filamins are preserved in C. elegans FLN-1 and FLN-2, and suggest the nematode may be a very useful model system for further study of filamin function.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Amino Acid Motifs
  • Animals
  • Caenorhabditis elegans / genetics*
  • Caenorhabditis elegans Proteins / chemistry*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Conserved Sequence
  • Contractile Proteins / chemistry*
  • Contractile Proteins / genetics
  • Contractile Proteins / metabolism*
  • Filamins
  • Gene Expression Regulation
  • Genomics
  • Humans
  • Immunoglobulins / chemistry
  • Microfilament Proteins / chemistry*
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Models, Molecular
  • Protein Structure, Tertiary
  • Protein Transport
  • Structural Homology, Protein

Substances

  • Actins
  • Caenorhabditis elegans Proteins
  • Contractile Proteins
  • FLNA protein, human
  • Filamins
  • Immunoglobulins
  • Microfilament Proteins