Manganese effectively supports yeast cell-cycle progression in place of calcium.

Abstract

Abstract. Metal ion requirements for the proliferation of Saccharomyces cerevisiae were investigated. We used bis- ( o-aminophenoxy )-ethane-N,N,N ',N '-tetraacetic acid (BAPTA), a relatively acid tolerant chelator, to reduce the free metal ion concentrations in culture media. Chelatable metal ions were added back individually and in combination. In addition to a requirement for ~10 pM external free Zn 2+ we found an interchangeable requirement for either 66 nM free Ca 2÷ or only 130 pM free Mn 2+. Cells depleted of Mn 2+ and Ca 2÷ arrested as viable cells with 2 N nuclei and tended to have very small minibuds. In the absence of added Mn 2÷, robust growth required --~60 IxM total internal Ca 2÷. In the presence of added Mn 2+, robust growth continued even when internal Ca 2+ was <3% this level. Chelatorfree experiments showed that MnCI2 strongly and CaC12 weakly restored high-temperature growth of cdcl ts strains which similarly arrest as viable cells with 2 N nuclear contents and small buds. Its much greater effectiveness compared with Ca 2+ suggests that Mn 2+ is likely to be a physiologic mediator of bud and nuclear development in yeast. This stands in marked contrast to a claim that Ca 2+ is uniquely required for cell-cycle progression in yeast. We discuss the possibility that Mn 2+ may function as an intracellular signal transducer and how this possibility relates to previous claims of Ca 2+'s roles in yeast metabolism. (Goscin and Fridovich, 1972;Bragg, 1974;Busse, 1984;Baum et al., 1986;Eisen et al., 1988;Anraku et al., 1991), a rigorous survey of nutritional metal ion requirements of yeast has never been undertaken. The recipe of yeast synthetic medium (SD) 1 in common use today was formulated over 40 years ago as a general medium for a diverse array of fungi (Wickersham, 1951). The ingredients of this medium include, besides those of Mg 2÷ and monovalents, salts of Ca 2+, Mn 2+, Cu 2+, Zn 2+, and Fe 3+. These five metal ions ranked essential, because they were dietary requirements of mammals and were present in trace amounts in yeast ash. Withholding from the medium the supplements of all five of these essential metal ions, including Ca 2+, does not stop growth, though. Such a culture presumably thrives on residual metal ions contaminating the medium. Even the addition of as much as 10 mM of the metal-ion chelator EGTA to synthetic medium containing only contaminat- ESPITE biochemical and genetic evidence for metal ion use in Saccharomyces cerevisiae

The Ca2+ Homeostasis Defects in a pgm2Δ Strain of Saccharomyces cerevisiae Are Caused by Excessive Vacuolar Ca2+ Uptake Mediated by the Ca2+-ATPase Pmc1p

“…Both of these processes are dependent upon the presence of Ca 2ϩ or Mn 2ϩ . Complicating the use of these assays to estimate compartmental Ca 2ϩ levels is the fact that Mn 2ϩ can effectively replace the requirement for Ca 2ϩ to promote the growth of yeast cells (40), and Mn 2ϩ was found to suppress the defects in invertase glycosylation caused by the pmr1 mutation more effectively than Ca 2ϩ (22). Thus, these results did not provide conclusive evidence that the Ca 2ϩ level was normal in either compartment.…”

Golgi Manganese Transport Is Required for Rapamycin Signaling in Saccharomyces cerevisiae

“…Deletion of PMR1 in sod1D sod2D (PJKP-1) also enhances the rapamycin-resistant phenotype. (Loukin and Kung 1995). Additions of Ca 21 to media (1-10 mm) did not increase rapamycin resistance of BY4741 or TB50a (supplemental data at http:// www.genetics.org/supplemental/).…”

Organellar mechanosensitive channels in fission yeast regulate the hypo-osmotic shock response

“…Interestingly, MnCl 2 , which can replace the functions of Ca 2 + (ref. 31), decreased viability upon hypo-osmotic shock, as with CaCl 2 . The viability of msy1 -msy2 -cells was decreased as the CaCl 2 concentration in the hypo-osmotic solution was increased, whereas that of WT, msy1 -and msy2 -cells was not changed (Fig.…”