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XvVHA‐c′′1 – a novel stress‐responsive V‐ATPase subunit c′′ homologue isolated from the resurrection plant Xerophyta viscosa
Author(s) -
Marais Saberi,
Thomson Jennifer A.,
Farrant Jill M.,
Mundree Sagadevan G.
Publication year - 2004
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2004.00389.x
Subject(s) - biology , complementation , transmembrane domain , protein subunit , biochemistry , saccharomyces cerevisiae , arabidopsis thaliana , atp synthase , microbiology and biotechnology , mutant , amino acid , gene
The strategy of ‘complementation by functional sufficiency’ was used to isolate XvVHA‐c′′1 , a vacuolar adenosine triphosphatase (V‐ATPase) proteolipid subunit c′′ homologue from Xerophyta viscosa . XvVHA‐c′′1 rescued Escherichia coli srl ::Tn10 mutants that were subjected to a 1.2 M sorbitol osmotic stress. Bioinformatics analyses conducted on XvVHA‐c′′1 revealed all signature characteristics that are common amongst subunit c homologues, which include the four transmembrane domain motifs and a conserved glutamate residue in the fourth transmembrane domain. XvVHA‐c′′1 shares 90.96% identity with the Oryza sativa (japonica) subunit c homologue and 86.67% identity with a putative vacuolar ATP synthase proteolipid subunit c′ from Arabidopsis thaliana , at the amino acid level. Southern hybridization analysis conducted on X. viscosa genomic DNA confirmed the presence of XvVHA‐c′′1 in the X. viscosa genome. Northern hybridization analysis was conducted on X. viscosa tissue subjected to NaCl stress, dehydration and − 20°C shock, in response to which upregulated transcript levels of XvVHA‐c′′1 were seen. XvVHA‐c′′1 's functional relevance was established through complementation using a Saccharomyces cerevisiae vma3 knockout.