A novel gene, ecl1+, extends the chronological lifespan in fission yeast

Abstract

We have identified a novel gene from Schizosaccharomyces pombe that we have named ecl1(+) (extender of the chronological lifespan). When ecl1(+) is provided on a high-copy number plasmid, it extends the viability of both the Deltasty1 MAP kinase mutant and the wild-type cells after entry into the stationary phase. ecl1(+) encodes an 80-amino acid polypeptide that had not been annotated in the current database. The ecl1(+)-mRNA increases transiently when the growth phase is changed from the log phase to the stationary phase. The Ecl1 protein is localized in the nucleus. Calorie restriction extends the chronological lifespan of wild-type and Deltaecl1 cells but not ecl1(+)-overproducing cells. The Deltapka1 mutant shows little, if any, additional extension of viability when Ecl1 is overproduced. The ste11(+) gene that is negatively controlled by Pka1 is up regulated when Ecl1 is overproduced. From these results we propose that the effect of Ecl1 overproduction may be mainly linked to and negatively affects the Pka1-dependent pathway.

The Fission Yeastphp2Mutant Displays a Lengthened Chronological Lifespan

“…6,7) When each of these genes was overexpressed, the cell survival rate in the stationary phase was higher than that of the controls. We also identified the ECL1 (YGR146c) gene in S. cerevisiae as a functional homolog of the Ecl1 family genes in S. pombe.…”

“…Previously we reported that overexpression of Ecl1 causes physiological changes equivalent to the changes caused by CR. 6) Therefore the chronological lifespan of Áphp2 mutant may be extended by mimicking CR.…”

“…The amplified DNA fragment was digested with BglII and SalI and then cloned into pLB-Dblet to construct pPhp2. The pEcl1 plasmid used for overexpression of ecl1 þ is described in Ohtsuka et al (2008). 6) Plasmids pEcl2 and pEcl3, used for overexpression of ecl2 þ and ecl3 þ respectively, are described in Ohtsuka et al (2009).…”

“…These encode highly homologous small proteins and extend the lifespan of fission yeast when overexpressed. 6,7) ecl1 þ -mRNA is induced by nitrogen starvation and ecl2 þ -mRNA by heat shock, suggesting that Ecl1 family genes evolved to respond to different stressors and to survive under unfavorable conditions. 8,9) Ecl1 family genes appear to execute their functions primarily through the prr1 þ gene, which is a twocomponent system response regulator, and partially through the hsr1 þ gene, which encodes a zinc finger transcription factor similar to Msn2 of S. cerevisiae.…”

“…Northern hybridization analysis was performed as described previously. 6) Cells were grown in SD medium, and collected at each growth phase, and total RNA fractions were prepared. After denaturation with formamide-formaldehyde, RNA (10 mg) was analyzed on a 1.2% agarose gel containing formaldehyde.…”