Acanthamoeba healyi: molecular cloning and characterization of a coronin homologue, an actin-related protein

Exp Parasitol. 2005 Jun;110(2):114-22. doi: 10.1016/j.exppara.2005.02.007. Epub 2005 Mar 23.

Abstract

Coronin, described in organisms from yeasts to humans, has been found to be involved in various actin-associated activities. It has yet to be described in Acanthamoeba, medically significant as the causative agent of granulomatous amebic encephalitis and amoebic keratitis and used extensively in actin-related studies. We isolated and characterized a cDNA encoding a coronin-like protein in A. healyi by sequence analysis and demonstrated intracellular localization of the gene product by transient transfection. Named Ahcoronin, the gene is composed of 454 amino acids which contain the characteristic WD repeats of coronin and coronin-like proteins. The C-terminal region of the gene was also predicted to have a high tendency of forming a coiled-coil, another structural characteristic of coronin. The gene showed a 50% homology to coronins. Ahcoronin occurs as a single copy and expressed as a transcript of approximately 1.4kb in A. healyi. Results of transfection showed that Ahcoronin was localized in the cell's periphery and in the leading edge consistent to that of actin. The fusion protein has also been observed to localize around phagocytic cups but was disassembled later during phagocytosis. Sequence analysis of Ahcoronin homologue of A. healyi showed numerous potential for further studies and is sure to contribute in the growing interest toward the properties and functions of coronin and coronin-like proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acanthamoeba / chemistry
  • Acanthamoeba / classification
  • Acanthamoeba / genetics*
  • Actins / chemistry
  • Actins / genetics*
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blotting, Northern
  • Blotting, Southern
  • Cloning, Molecular
  • DNA, Complementary / chemistry
  • DNA, Protozoan / chemistry*
  • Genetic Vectors
  • Green Fluorescent Proteins / analysis
  • Humans
  • Microfilament Proteins / chemistry
  • Microfilament Proteins / genetics*
  • Microscopy, Fluorescence
  • Molecular Sequence Data
  • Phagocytosis
  • Phylogeny
  • Protozoan Proteins / chemistry
  • Protozoan Proteins / genetics*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Transfection

Substances

  • Actins
  • DNA, Complementary
  • DNA, Protozoan
  • Microfilament Proteins
  • Protozoan Proteins
  • enhanced green fluorescent protein
  • coronin proteins
  • Green Fluorescent Proteins