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The ZntA-like NpunR4017 plays a key role in maintaining homeostatic levels of zinc in Nostoc punctiforme

Version 2 2024-06-04, 03:37
Version 1 2015-09-30, 15:42
journal contribution
posted on 2024-06-04, 03:37 authored by L Hudek, Lambert BrauLambert Brau, Agnes MichalczykAgnes Michalczyk, BA Neilan, JC Meeks, Leigh AcklandLeigh Ackland
Analysis of cellular response to zinc exposure provides insights into how organisms maintain homeostatic levels of zinc that are essential, while avoiding potentially toxic cytosolic levels. Using the cyanobacterium Nostoc punctiforme as a model, qRT-PCR analyses established a profile of the changes in relative mRNA levels of the ZntA-like zinc efflux transporter NpunR4017 in response to extracellular zinc. In cells treated with 18 μM of zinc for 1 h, NpunR4017 mRNA levels increased by up to 1300 % above basal levels. The accumulation and retention of radiolabelled (65)Zn by NpunR4107-deficient and overexpressing strains were compared to wild-type levels. Disruption of NpunR4017 resulted in a significant increase in zinc accumulation up to 24 % greater than the wild type, while cells overexpressing NpunR4107 accumulated 22 % less than the wild type. Accumulation of (65)Zn in ZntA(-) Escherichia coli overexpressing NpunR4017 was reduced by up to 21 %, indicating the capacity for NpunR4017 to compensate for the loss of ZntA. These findings establish the newly identified NpunR4017 as a zinc efflux transporter and a key transporter for maintaining zinc homeostasis in N. punctiforme.

History

Journal

Applied microbiology and biotechnology

Volume

99

Pagination

10559-10574

Location

New York, N.Y.

ISSN

1432-0614

eISSN

1432-0614

Language

eng

Publication classification

C Journal article, C1 Refereed article in a scholarly journal

Copyright notice

2015, Springer

Issue

24

Publisher

Springer