Small heat-shock protein Hsp9 has dual functions in stress adaptation and stress-induced G2-M checkpoint regulation via Cdc25 inactivation in Schizosaccharomyces pombe

Heat shock protein 9 mRNA expression increases during fruiting body differentiation in Grifola frondosa and other edible mushrooms

“…Analysis of a deletion mutant of DHSP12 suggested the HSP12 gene is important for the survival of S. cerevisiae against heat shock, oxidative stress, osmotic stress, and cellular aging (Welker et al 2010). HSP9/12, a homolog of S. cerevisiae HSP12 in Schizosaccharomyces pombe and Candida albicans, undergoes the same elevation in expression at HSP12 upon entry into the stationary phase and in response to stress (Orlandi et al 1996;Ahn et al 2011;Fu et al 2012). Thus, fungal HSP9/12 likely also plays an important role in stress adaptation.…”

“…For comparison of control elements, the S. cerevisiae HSP12 promoter has two putative TATA boxes and two heat shock elements (HSE) of consensus sequence CNNGAANNTTCNNGG (Praekelt and Meacock 1990). In S. pombe, the HSP9 promoter has a TATA box and another HSE consisting of arrays of the 5-bp unit AGAAN arranged as inverted repeats, and three stress-responsive CCCCT (or AGGGG) motifs (STRE) (Ahn et al 2011). In contrast, in the Gf.HSP9 promoter, the TATA box-like sequence was found 99 bp upstream of the ATG start codon and two STRE occur at 429 bp and 457 bp upstream of the start codon.…”

Moonlighting chaperone‐like activity of the universal regulatory 14‐3‐3 proteins

“…Hsp9-14-3-3 complex interacts with Cdc25, modulating its phosphatase activity and by this means regulating activity of Cdc2 and the cell cycle Probably phosphorylation dependent [87] Hsp70 homolog Ssb Bmh1 Forms a chaperone module regulating a switch between respiration and fermentation Probably phosphorylation dependent [88] aB-crystallin (HspB5) f In hepatocarcinoma, 14-3-3-aB-crystallin complex upregulates ERK1/2 activity, prevents effect of protein kinase inhibitor sorafenib and induces epithelialmesenchymal transition Phosphorylation independent [89] Hsp20 (HspB6) c, f Different isoforms of 14-3-3 interact with phosphorylated HspB6 and modulate its chaperone-like activity and regulatory functions Phosphorylation dependent [91,93] Model substrates Citrate synthase f Inhibition of heat-induced amorphous aggregation Phosphorylation independent [52] Insulin, rhodanase c Inhibition of heat-or reduction-induced amorphous aggregation Phosphorylation independent [91] Insulin, alcohol dehydrogenase f Inhibition of heat-or reduction-induced amorphous aggregation Phosphorylation independent [96] that the amphipathic groove of 14-3-3 is directly involved in the chaperone-like activity of 14-3-3. Intriguingly, in analyzing the chaperone-like activity, we found that monomeric forms usually possessed higher activity than dimeric forms of 14-3-3, irrespective of the model substrate used (see above) [24,97].…”

Development of episomal vectors carrying a nourseothricin‐resistance marker for use in minimal media for Schizosaccharomyces pombe

“…pombe hsp9 + gene was cloned into the vectors pDES175N carrying the LEU2 marker (Ahn et al ., ) and pDES176 carrying the NAT marker, and the localization of the GFP–hsp9 fusion protein expressed from these vectors, pDES175N– hsp9 + and pDES176– hsp9 + , was compared. In agreement with our previous study (Ahn et al ., ), we observed that GFP– hsp9 + fusion proteins expressed from pDES175N– hsp9 + and pDES176– hsp9 + were localized in the nucleus after heat shock, indicating that these vectors are valuable tools for the production of heterologous proteins, similar to auxotrophic marker vectors in Sz. pombe .…”