Journal
TUBERCULOSIS
Volume 132, Issue -, Pages -Publisher
CHURCHILL LIVINGSTONE
DOI: 10.1016/j.tube.2021.102162
Keywords
The mce operon; Lipid transport; Mycobacterium tuberculosis; Cell wall homeostasis
Categories
Funding
- INTA [I103, I105]
- FonCyT, Argentina [PICT-2016-1688]
- Austrian Science Fund (FWF) [I105] Funding Source: Austrian Science Fund (FWF)
Ask authors/readers for more resources
MCE genes are found in various mycobacterial species and may not only be associated with virulence, but also involved in response to external stress conditions. Additionally, they are considered to function similarly to ABC transporters.
Mammalian cell entry (mce) genes are not only present in genomes of pathogenic mycobacteria, including Mycobacterium tuberculosis (the causative agent of tuberculosis), but also in saprophytic and opportunistic mycobacterial species. MCE are conserved cell-wall proteins encoded by mce operons, which maintain an identical structure in all mycobacteria: two yrbE genes (A and B) followed by six mce genes (A, B, C, D, E and F). Although these proteins are known to participate in the virulence of pathogenic mycobacteria, the presence of the operons in nonpathogenic mycobacteria and other bacteria indicates that they play another role apart from host cell invasion. In this respect, more recent studies suggest that they are functionally similar to ABC transporters and form part of lipid transporters in Actinobacteria. To date, most reviews on mce operons in the literature discuss their role in virulence. However, according to data from transcriptional studies, mce genes, particularly the mce1 and mce4 operons, modify their expression according to the carbon source and upon hypoxia, starvation, surface stress and oxidative stress; which suggests a role of MCE proteins in the response of Mycobacteria to external stressors. In addition to these data, this review also summarizes the studies demonstrating the role of MCE proteins as lipid transporters as well as the relevance of their transport function in the interaction of pathogenic Mycobacteria with the hosts. Altogether, the evidence to date would indicate that MCE proteins participate in the response to the stress conditions that mycobacteria encounter during infection, by participating in the cell wall remodelling and possibly contributing to lipid homeostasis.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available