Skip to Main content Skip to Navigation
Journal articles

Microsporidia amitochondrial protists possess a 70-kDa heat shock protein gene of mitochondrial evolutionary origin

Abstract : An intronless gene encoding a protein of 592 amino acid residues with similarity to 70-kDa heat shock proteins (HSP70s) has been cloned and sequenced from the amitochondrial protist Encephalitozoon cuniculi (phylum Microsporidia). Southern blot analyses show the presence of a single gene copy located on chromosome XI. The encoded protein exhibits an N-terminal hydrophobic leader sequence and two motifs shared by proteobacterial and mitochondrially expressed HSP70 homologs. Phylogenetic analysis using maximum likelihood and evolutionary distances place the E. cuniculi sequence in the cluster of mitochondrially expressed HSP70s, with a higher evolutionary rate than those of homologous sequences. Similar results were obtained after cloning a fragment of the homologous gene in the closely related species E. hellem. The presence of a nuclear targeting signal-like sequence supports a role of the Encephalitozoon HSP70 as a molecular chaperone of nuclear proteins. No evidence for cytosolic or endoplasmic reticulum forms of HSP70 was obtained through PCR amplification. These data suggest that Encephalitozoon species have evolved from an ancestor bearing mitochondria, which is in disagreement with the postulated presymbiotic origin of Microsporidia. The specific role and intracellular localization of the mitochondrial HSP70-like protein remain to be elucidated.
Document type :
Journal articles
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-00428498
Contributor : Stéphane Delmotte Connect in order to contact the contributor
Submitted on : Wednesday, October 28, 2009 - 5:32:20 PM
Last modification on : Monday, October 4, 2021 - 2:52:05 PM

Links full text

Identifiers

Collections

Citation

E. Peyretaillade, V. Broussolle, P. Peyret, G. Metenier, Manolo Gouy, et al.. Microsporidia amitochondrial protists possess a 70-kDa heat shock protein gene of mitochondrial evolutionary origin. Molecular Biology and Evolution, Oxford University Press (OUP), 1998, 15, pp.683-689. ⟨10.1093/oxfordjournals.molbev.a025971⟩. ⟨hal-00428498⟩

Share

Metrics

Record views

271