In:
Molecular Microbiology, Wiley, Vol. 97, No. 5 ( 2015-09), p. 881-897
Abstract:
Sphingomyelinases secreted by pathogenic bacteria play important roles in host–pathogen interactions ranging from interfering with phagocytosis and oxidative burst to iron acquisition. This study shows that the M tb protein R v0888 possesses potent sphingomyelinase activity cleaving sphingomyelin, a major lipid in eukaryotic cells, into ceramide and phosphocholine, which are then utilized by M tb as carbon, nitrogen and phosphorus sources, respectively. An M tb rv0888 deletion mutant did not grow on sphingomyelin as a sole carbon source anymore and replicated poorly in macrophages indicating that M tb utilizes sphingomyelin during infection. R v0888 is an unusual membrane protein with a surface‐exposed C ‐terminal sphingomyelinase domain and a putative N ‐terminal channel domain that mediated glucose and phosphocholine uptake across the outer membrane in an M . smegmatis porin mutant. Hence, we propose to name R v0888 as SpmT ( sp hingomyelinase of M ycobacterium t uberculosis ). Erythrocyte membranes contain up to 27% sphingomyelin. The finding that R v0888 accounts for half of M tb's hemolytic activity is consistent with its sphingomyelinase activity and the observation that R v0888 levels are increased in the presence of erythrocytes and sphingomyelin by 5‐ and 100‐fold, respectively. Thus, R v0888 is a novel outer membrane protein that enables M tb to utilize sphingomyelin as a source of several essential nutrients during intracellular growth.
Type of Medium:
Online Resource
ISSN:
0950-382X
,
1365-2958
DOI:
10.1111/mmi.2015.97.issue-5
Language:
English
Publisher:
Wiley
Publication Date:
2015
detail.hit.zdb_id:
1501537-3
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