Mammalian Homologue of E. Coli Ras-like GTPase (ERA) Is a Possible Apoptosis Regulator With RNA Binding Activity

Genes Cells. 2001 Nov;6(11):987-1001. doi: 10.1046/j.1365-2443.2001.00480.x.

Abstract

Background: ERA (Escherichia coli Ras-like protein) is an E. coli GTP binding protein that is essential for proliferation. A DNA database search suggests that homologous sequences with ERA exist in various organisms including human, mouse, Drosophila, Caenorhabditis elegans and Antirrhinum majus. However, the physiological function of eukaryotic ERA-like proteins is not known.

Results: We have cloned cDNAs encoding the entire coding region of a human homologue (H-ERA) and a mouse homologue (M-ERA) of ERA. The mammalian homologue of ERA consists of a typical GTPase/GTP-binding domain and a putative K homology (KH) domain, which is known as an RNA binding domain. We performed transfection experiments with wild-type H-ERA or various H-ERA mutants. H-ERA possessing the amino acid substitution mutation into the GTPase domain induced apoptosis of HeLa cells, which was blocked by Bcl-2 expression. Deletion of the C-terminus, which contains a part of the KH domain, alleviated apoptosis by the H-ERA mutant, suggesting the importance of this domain in the function of H-ERA. We have also shown the RNA binding activity of H-ERA by pull-down experiments using RNA homopolymer immobilized on beads or recombinant H-ERA proteins.

Conclusion: Our data suggest that H-ERA plays an important role in the regulation of apoptotic signalling with its GTPase/GTP binding domain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Apoptosis / physiology*
  • Base Sequence
  • Blotting, Northern
  • DNA Primers
  • Escherichia coli / enzymology*
  • Escherichia coli Proteins*
  • Fluorescent Antibody Technique
  • GTP-Binding Proteins / chemistry
  • GTP-Binding Proteins / genetics
  • GTP-Binding Proteins / physiology*
  • HeLa Cells
  • Humans
  • In Situ Nick-End Labeling
  • Molecular Sequence Data
  • Mutation
  • Protein Processing, Post-Translational
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • RNA-Binding Proteins / chemistry
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / physiology*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • bcl-X Protein

Substances

  • BCL2L1 protein, human
  • DNA Primers
  • Escherichia coli Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • RNA-Binding Proteins
  • Recombinant Proteins
  • bcl-X Protein
  • era protein, E coli
  • GTP-Binding Proteins