Mutations in the gene that encodes the F-actin binding protein anillin cause FSGS

J Am Soc Nephrol. 2014 Sep;25(9):1991-2002. doi: 10.1681/ASN.2013090976. Epub 2014 Mar 27.

Abstract

FSGS is characterized by segmental scarring of the glomerulus and is a leading cause of kidney failure. Identification of genes causing FSGS has improved our understanding of disease mechanisms and points to defects in the glomerular epithelial cell, the podocyte, as a major factor in disease pathogenesis. Using a combination of genome-wide linkage studies and whole-exome sequencing in a kindred with familial FSGS, we identified a missense mutation R431C in anillin (ANLN), an F-actin binding cell cycle gene, as a cause of FSGS. We screened 250 additional families with FSGS and found another variant, G618C, that segregates with disease in a second family with FSGS. We demonstrate upregulation of anillin in podocytes in kidney biopsy specimens from individuals with FSGS and kidney samples from a murine model of HIV-1-associated nephropathy. Overexpression of R431C mutant ANLN in immortalized human podocytes results in enhanced podocyte motility. The mutant anillin displays reduced binding to the slit diaphragm-associated scaffold protein CD2AP. Knockdown of the ANLN gene in zebrafish morphants caused a loss of glomerular filtration barrier integrity, podocyte foot process effacement, and an edematous phenotype. Collectively, these findings suggest that anillin is important in maintaining the integrity of the podocyte actin cytoskeleton.

Publication types

  • Research Support, American Recovery and Reinvestment Act
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Adult
  • Aged
  • Amino Acid Sequence
  • Animals
  • Cell Movement / genetics
  • Conserved Sequence
  • Contractile Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • DNA Mutational Analysis
  • Disease Models, Animal
  • Exome
  • Female
  • Gene Knockdown Techniques
  • Glomerular Filtration Barrier / metabolism
  • Glomerulosclerosis, Focal Segmental / genetics*
  • Glomerulosclerosis, Focal Segmental / pathology
  • Humans
  • Male
  • Mice
  • Microfilament Proteins / genetics*
  • Middle Aged
  • Molecular Sequence Data
  • Mutant Proteins / genetics
  • Mutation*
  • Pedigree
  • Podocytes / metabolism
  • Sequence Homology, Amino Acid
  • Up-Regulation
  • Zebrafish
  • Zebrafish Proteins / genetics

Substances

  • ANLN protein, human
  • Adaptor Proteins, Signal Transducing
  • CD2-associated protein
  • Contractile Proteins
  • Cytoskeletal Proteins
  • Microfilament Proteins
  • Mutant Proteins
  • Zebrafish Proteins
  • anillin