Membrane vesicles, nanopods and/or nanotubes produced by hyperthermophilic archaea of the genus Thermococcus.
Thermococcus species produce MVs (membrane vesicles) into their culture medium. These MVs are formed by a budding process from the cell envelope, similar to ectosome formation in eukaryotic cells. The major protein present in MVs of Thermococci is a peptide-binding receptor of the OppA (oligopeptide-binding protein A) family. In addition, some of them contain a homologue of stomatin, a universal membrane protein involved in vesiculation. MVs produced by Thermococcus species can recruit endogenous or exogenous plasmids and plasmid transfer through MVs has been demonstrated in Thermococcus kodakaraensis. MVs are frequently secreted in clusters surrounded by S-layer, producing either big protuberances (nanosphere) or tubular structures (nanotubes). Thermococcus gammatolerans and T. kodakaraensis produce nanotubes containing strings of MVs, resembling the recently described nanopods in bacteria, whereas Thermococcus sp. 5-4 produces filaments whose internal membrane is continuous. These nanotubes can bridge neighbouring cells, forming cellular networks somehow resembling nanotubes recently observed in Firmicutes. As suggested for bacteria, archaeal nanopods and/or nanotubes could be used to expand the metabolic sphere around cells and/or to promote intercellular communication.
Institut de Génétique et Microbiologie, Université Paris-Sud, CNRS UMR8621, 91405 Orsay Cedex, France. evelyne.marguet@igmors.u-psud.fr
Evelyne
E
Marguet
Marie
M
Gaudin
Emilie
E
Gauliard
Isabelle
I
Fourquaux
Stephane
S
le Blond du Plouy
Ikuo
I
Matsui
Patrick
P
Forterre
D019843:Archaeal Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003470:Culture Media; D019641:DNA, Archaeal / Q000235:genetics; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes; D019712:Thermococcus / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure
D019843:Archaeal Proteins; D003470:Culture Media; D019641:DNA, Archaeal