Premium
Mitochondrial Porin VDAC 1 Seems to Be Functional in Rickettsial Cells
Author(s) -
Emelyanov Victor V.
Publication year - 2009
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2009.04513.x
Subject(s) - porin , voltage dependent anion channel , rickettsia prowazekii , bacterial outer membrane , biology , rickettsia , vdac1 , mitochondrion , organelle , spotted fever , microbiology and biotechnology , biochemistry , virology , escherichia coli , virus , gene
We have recently shown that Rickettsia prowazekii (typhus group rickettsiae) cells incorporate human mitochondrial porin VDAC1. Here, I report on the import of porin by rickettsiae of spotted fever group. It was shown that rickettsial cells of heavy band of Renografin density gradient, known as permeabilized rickettsiae, contain much more VDAC 1 compared to the cells of light band, that is, non‐permeabilized rickettsiae. These data hint at a functionality of mitochondrial porin in rickettsial cells. The cells of Rickettsia canadensis were broken in French‐press, and total membranes were fractionated on linear sucrose density gradient. In this way, previous data were confirmed that an outer rickettsial membrane does not contain porin, while fraction of intermediate density, which likely represents Bayer's adhesion zones, is enriched in VDAC 1. This is consistent with earlier results and their interpretation that imported porin seems to localize to contact sites between inner and outer rickettsial membranes. Based on well‐known phylogenetic relationship of Rickettsiales and mitochondria, an evolutionary scenario for the origin of protein import machinery is proposed. A dependence of rickettsiae upon essential protein(s), destined to organelle, is also viewed as a nature of their obligate endosymbiotic lifestyle.