A bacteria-derived tail anchor localizes to peroxisomes in yeast and mammalian cells

Abstract

Prokaryotes can provide new genetic information to eukaryotes by horizontal gene transfer (HGT), and such transfers are likely to have been particularly consequential in the era of eukaryogenesis. Since eukaryotes are highly compartmentalized, it is worthwhile to consider the mechanisms by which newly transferred proteins might reach diverse organellar destinations. Toward this goal, we have focused our attention upon the behavior of bacteria-derived tail anchors (TAs) expressed in the eukaryote Saccharomyces cerevisiae. In this study, we report that a predicted membrane-associated domain of the Escherichia coli YgiM protein is specifically trafficked to peroxisomes in budding yeast, can be found at a pre-peroxisomal compartment (PPC) upon disruption of peroxisomal biogenesis, and can functionally replace an endogenous, peroxisome-directed TA. Furthermore, the YgiM(TA) can localize to peroxisomes in mammalian cells. Since the YgiM(TA) plays no endogenous role in peroxisomal function or assembly, this domain is likely to serve as an excellent tool allowing further illumination of the mechanisms by which TAs can travel to peroxisomes. Moreover, our findings emphasize the ease with which bacteria-derived sequences might target to organelles in eukaryotic cells following HGT, and we discuss the importance of flexible recognition of organelle targeting information during and after eukaryogenesis.

YgiM may act as a trigger in the sepsis caused by Klebsiella pneumoniae through the membrane-associated ceRNA network

“…YgiM, an inner membrane protein, was firstly reported in E. coli, and it was confirmed to be anchored to peroxisomes in yeast and mammalian cells (Maddalo et al, 2011;Lutfullahoglu-Bal et al, 2018). Through homology alignment, we found a homologous gene vk055_4013 with 83% high similarity to ygiM in the genome of K. pneumoniae ATCC 43816.…”

“…Studies have shown that K. pneumoniae is the major pathogen causing localized infections such as pneumonia and liver abscesses, and disseminated infections that can lead to severe sepsis (Chew, Lin, and Teo 2017). In K. pneumoniae, the inner membrane protein YgiM has been shown to play an important role by localizing peroxisomes in yeast and mammalian cells (Lutfullahoglu-Bal et al, 2018). The present study explored whether YgiM protein deficiency affects the process of K. pneumoniae interfering with the host, and revealed a membrane associated ceRNAs network of YgiM protein in K. pneumoniae induced sepsis.…”

Proteins that carry dual targeting signals can act as tethers between peroxisomes and partner organelles

“…Alternatively, direct dislocation and subsequent insertion into peroxisomes may occur. The ATPase Spf1 is involved in dislocation of TA proteins from the ER and in peroxisome biogenesis and function [16,[58][59][60]. To test whether this protein is required for sorting of Pex15 from the ER to peroxisomes, we analyzed the localization of Pex15 fused to the bright fluorescent protein mNeonGreen in Δspf1 cells.…”

The subset of peroxisomal tail-anchored proteins do not reach peroxisomes via ER, instead mitochondria can be involved

“…To test whether peroxisomal TA proteins insert into the ER on their way to peroxisomes, we used a previously described model protein YgiM(TA), a bacterial derived sequence, shown to specifically target peroxisomes in mammalian cells [20]. As a reporter for protein entry into the ER we used opsin glycosylation tag (OPG) since it contains a glycosylation site which accepts glycans if exposed to the ER lumen [21].…”