Possible involvement of GDI1 protein, a GDP dissociation inhibitor related to vesicle transport, in an amelioration of zinc toxicity in Saccharomyces cerevisiae

Abstract

The GDI1 protein related vesicle transport system was studied to investigate the possibility that an exclusion of toxic zinc (Zn) from the cytoplasm ameliorates Zn toxicity in Saccharomyces cerevisiae (yeast). A temperature-sensitive gdi1 mutant (originally called sec19), in which the GDP dissociation inhibitor becomes inactive at the non-permissive temperature (37 C), was more sensitive to Zn than its parental GDI1 strain at 32 C (a moderately non-permissive temperature). The relative efflux of cytoplasmic Zn in the gdi1 mutant was lower than that in the control strain. Treatment with a vesicle transport-specific inhibitor, Brefeldin A, caused an increase of Zn sensitivity and a decrease of Zn efflux in these strains. It is therefore suggested that the GDI1-related vesicle transport system contributes to Zn tolerance in yeast. Furthermore, changes in the number of Zn-specific fluorescent granules (zincosomes) were observed by zinquin staining in the mutant cells under Zn treatment at 32 C and 37 C. We concluded that the GDI1 protein is implicated in control of vesicle numbers. Collectively, the results suggest that the GDI1protein is involved in Zn efflux via small vesicle trafficking and contributes to the control of cytoplasmic Zn content, allowing yeast to survive in the presence of toxic Zn.

MiRNAs profiling and degradome sequencing between the CMS-line N816S and its maintainer line Ning5m during anther development in pepper (Capsicum annuumL.)

“…In Arabidopsis, AtGIP1 and its homologous protein AtGIP2 mutants are impaired in establishing a fully functional mitotic spindle and exhibit severe developmental defects(Batzenschlager et al, 2013). The GDP dissociation inhibitor protein GDI1 relates to control vesicle number and transport in an amelioration of zinc toxicity, allowing yeast to survive in the presence of toxic(Ezaki and Nakakihara, 2012). Furthermore, Digalactosyl-diacylglycerol (DGD) is one of the major lipids found predominantly in the photosynthetic membrane of higher plants.…”

Enhancing cognition through pharmacological and environmental interventions: Examples from preclinical models of neurodevelopmental disorders

“…This idea is borne out for a model of non-syndromic ID, the Gdi1-null mouse, which did not show the expected cognitive impairment when housed in mildly enriched environments but only when housing was a mildly impoverished environment (Bianchi et al, 2009;D'Adamo et al, 2014;De Giorgio, 2017). This may be explained by the neurobiology of the Gdi1-null mutant that curtails the benefit it can get from environmental enrichment, in spite of an increased number of dendritic spines this environment elicits in the brain (Correa et al, 2012;Daumas et al, 2017;Hunter et al, 2017): In Gdi1-null mice the presynaptic recycling of glutamatergic vesicles remains time-limited, hence the beneficial effects of enrichment remain curtailed and ineffective on some sustained tasks (Bianchi et al, 2009;D'Adamo et al, 2014;Ezaki and Nakakihara, 2012;More et al, 2017;Strobl-Wildemann et al, 2011). Finally, it is important to note that the proposed outcomes of this model also would be influenced by the age at which enrichment began, and the duration of exposure.…”

The COP9 signalosome is involved in the regulation of lipid metabolism and of transition metals uptake in Saccharomyces cerevisiae

“…To verify whether the low expression of zinc metabolism genes observed in Δcsn5 cells could be correlated to an alteration in zinc content, we checked zinc intracellular levels on cells grown in YPD using the fluorescent dye zinquin ethyl ester (see Materials and methods). This zinc-specific dye has already been used successfully to measure relative zinc levels in S. cerevisiae [36,37]. While poor zinquin staining was observed in wild-type cells grown under normal conditions, addition of 500 lM ZnSO 4 to the medium resulted in the formation of small, bright fluorescent granules (zincosomes) (Fig.…”