CtpB is a plasma membrane copper (I) transporting P-type ATPase of Mycobacterium tuberculosis
Biol. Res
;
53: 06, 2020. graf
Artigo
em Inglês
| LILACS
| ID: biblio-1089076
ABSTRACT
BACKGROUND:
The intracellular concentration of heavy-metal cations, such as copper, nickel, and zinc is pivotal for the mycobacterial response to the hostile environment inside macrophages. To date, copper transport mediated by P-type ATPases across the mycobacterial plasma membrane has not been sufficiently explored.RESULTS:
In this work, the ATPase activity of the putative Mycobacterium tuberculosis P1B-type ATPase CtpB was associated with copper (I) transport from mycobacterial cells. Although CtpB heterologously expressed in M. smegmatis induced tolerance to toxic concentrations of Cu2+ and a metal preference for Cu+, the disruption of ctpB in M. tuberculosis cells did not promote impaired cell growth or heavy-metal accumulation in whole mutant cells in cultures under high doses of copper. In addition, the Cu+ ATPase activity of CtpB embedded in the plasma mem-brane showed features of high affinity/slow turnover ATPases, with enzymatic parametersKM 0.19 ± 0.04 µM and Vmax 2.29 ± 0.10 nmol/mg min. In contrast, the ctpB gene transcription was activated in cells under culture conditions that mimicked the hostile intraphagosomal environment, such as hypoxia, nitrosative and oxidative stress, but not under high doses of copper.CONCLUSIONS:
The overall results suggest that M. tuberculosis CtpB is associated with Cu+ transport from mycobacterial cells possibly playing a role different from copper detoxification.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Membrana Celular
/
ATPases Transportadoras de Cobre
/
Mycobacterium tuberculosis
Idioma:
Inglês
Revista:
Biol. Res
Assunto da revista:
Biologia
Ano de publicação:
2020
Tipo de documento:
Artigo
País de afiliação:
Colômbia
Instituição/País de afiliação:
Universidad Nacional de Colombia/CO
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