Converts adenosine 3'-phosphate 5'-phosphosulfate (PAPS) to adenosine 5'-phosphosulfate (APS) and 3'(2')-phosphoadenosine 5'- phosphate (PAP) to AMP. Regulates the flux of sulfur in the sulfur-activation pathway by converting PAPS to APS. Involved in salt tolerance. Confers resistance to lithium. adenosine 3',5'-bisphosphate + H2O = AMP + phosphate

MALERELLVATQAVRKASLLTKRIQSEVISHKDSTTITKNDNSPVTTGDYAAQTIIINAI KSNFPDDKVVGEESSSGLSDAFVSGILNEIKANDEVYNKNYKKDDFLFTNDQFPLKSLED VRQIIDFGNYEGGRKGRFWCLDPIDGTKGFLRGEQFAVCLALIVDGVVQLGCIGCPNLVL SSYGAQDLKGHESFGYIFRAVRGLGAFYSPSSDAESWTKIHVRHLKDTKDMITLEGVEKG HSSHDEQTAIKNKLNISKSLHLDSQAKYCLLALGLADVYLRLPIKLSYQEKIWDHAAGNV IVHEAGGIHTDAMEDVPLDFGNGRTLATKGVIASSGPRELHDLVVSTSCDVIQSRNA362

	PMID	Title & Author	Abstract	Year
0	7493934	A rice HAL2-like gene encodes a Ca(2+)-sensitive 3'(2'),5'-diphosphonucleoside 3'(2')-phosphohydrolase and complements yeast met22 and Escherichia coli cysQ mutations.Z Peng , D P Verma	A plant homolog of yeast HAL2 gene (RHL) was cloned from rice (Orizya sativa L.). The RHL cDNA complemented an Escherichia coli cysteine auxotrophic mutant, cysQ, and the yeast HAL2 mutant, met22. The latter is a methionine auxotroph and cannot use sulfate, sulfite, or sulfide as sulfur sources but exhibits wild-type activities of the enzymes necessary to assimilate sulfate and has normal sulfur uptake system. These results demonstrated that HAL2, cysQ, and RHL genes encode proteins with similar function in sulfur assimilatory pathway. The RHL cDNA expressed a 40-kDa protein that was shown to catalyze the conversion of adenosine 3'-phosphate 5'-phosphosulfate (PAPS) to adenosine 5'-phosphosulfate (APS) and 3'(2')-phosphoadenosine 5'-phosphate (PAP) to AMP. The enzyme activity is Mg(2+)-dependent, sensitive to Ca2+, Li+, and Na+ and activated by K+. The inhibition by Ca2+ depends on the Mg2+/Ca2+ ratio and is reversible by high Mg2+ concentration. The substrate specificity and kinetics of RHL enzyme are very similar to the Chlorella 3'(2'),5'-diphosphonucleoside 3'(2')-phosphohydrolase (DPNPase). Our evidence suggests that this enzyme regulates the flux of sulfur in the sulfur-activation pathway by converting PAPS to APS. Several residues that are essential for the activity of this enzyme were identified by site-directed mutagenesis, and the possible role of DPNPase in salt tolerance is discussed.	1995
1	8721754	The SAL1 gene of Arabidopsis, encoding an enzyme with 3'(2'),5'-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase activities, increases salt tolerance in yeast.F J Quintero , B Garciadeblás, A Rodríguez-Navarro	A cDNA library in a yeast expression vector was prepared from roots of Arabidopsis exposed to salt and was used to select Li(+)-tolerant yeast transformants. The cDNA SAL1 isolated from one of these transformants encodes a polypeptide of 353 amino acid residues. This protein is homologous to the HAL2 and CysQ phosphatases of yeast and Escherichia coli, respectively. Partial cDNA sequences in the data bases indicate that rice produces a phosphatase highly homologous to SAL1 and that a second gene homologous to SAL1 exists in Arabidopsis. The SAL1 protein expressed in E. coli showed 3'(2'),5'-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase activities. In yeast, SAL1 restored the ability of a hal2/met22 mutant to grow on sulfate as a sole sulfur source, increased the intracellular Li+ tolerance, and modified Na+ and Li+ effluxes. We propose that the product of SAL1 participates in the sulfur assimilation pathway as well as in the phosphoinositide signaling pathway and that changes in the latter may affect Na+ and Li+ fluxes.	1996
2	8393782	Salt tolerance and methionine biosynthesis in Saccharomyces cerevisiae involve a putative phosphatase gene.H U Gläser , D Thomas, R Gaxiola, F Montrichard, Y Surdin-Kerjan, R Serrano	The progressive salinization of irrigated land poses a threat to the future of agriculture in arid regions. The identification of crucial metabolic steps in salt tolerance is important for the understanding of stress physiology and may provide the tools for its genetic engineering. In the yeast Saccharomyces cerevisiae we have isolated a gene, HAL2, which upon increase in gene dosage improves growth under NaCl and LiCl stresses. The HAL2 protein is homologous to inositol phosphatases, enzymes known to be inhibited by lithium salts. Complementation analysis demonstrated that HAL2 is identical to MET22, a gene involved in methionine biosynthesis. Accordingly, methionine supplementation improves the tolerance of yeast to NaCl and LiCl. These results demonstrate an unsuspected interplay between methionine biosynthesis and salt tolerance.	1993
3	30219856	Identification of novel genes involved in acetic acid tolerance of Saccharomyces cerevisiae using pooled-segregant RNA sequencing.Miguel Fernández-Niño , Sergio Pulido , Despina Stefanoska , Camilo Pérez , Daniel González-Ramos , Antonius J A van Maris , Kathleen Marchal , Elke Nevoigt , Steve Swinnen	Acetic acid tolerance of the yeast Saccharomyces cerevisiae is manifested in several quantifiable parameters, of which the duration of the latency phase is one of the most studied. It has been shown recently that the latter parameter is mostly determined by a fraction of cells within the population that resumes proliferation upon exposure to acetic acid. The aim of the current study was to identify genetic determinants of the difference in this parameter between the highly tolerant strain MUCL 11987-9 and the laboratory strain CEN.PK113-7D. To this end, a combination of genetic mapping and pooled-segregant RNA sequencing was applied as a new approach. The genetic mapping data revealed four loci with a strong linkage to strain MUCL 11987-9, each containing still a large number of genes making the identification of the causal ones by traditional methods a laborious task. The genes were therefore prioritized by pooled-segregant RNA sequencing, which resulted in the identification of six genes within the identified loci showing differential expression. The relevance of the prioritized genes for the phenotype was verified by reciprocal hemizygosity analysis. Our data revealed the genes ESP1 and MET22 as two, so far unknown, genetic determinants of the size of the fraction of cells resuming proliferation upon exposure to acetic acid.	2018
4	18443146	Degradation of several hypomodified mature tRNA species in Saccharomyces cerevisiae is mediated by Met22 and the 5'-3' exonucleases Rat1 and Xrn1.Irina Chernyakov , Joseph M Whipple, Lakmal Kotelawala, Elizabeth J Grayhack, Eric M Phizicky	Mature tRNA is normally extensively modified and extremely stable. Recent evidence suggests that hypomodified mature tRNA in yeast can undergo a quality control check by a rapid tRNA decay (RTD) pathway, since mature tRNA(Val(AAC)) lacking 7-methylguanosine and 5-methylcytidine is rapidly degraded and deacylated at 37 degrees C in a trm8-Delta trm4-Delta strain, resulting in temperature-sensitive growth. We show here that components of this RTD pathway include the 5'-3' exonucleases Rat1 and Xrn1, and Met22, which likely acts indirectly through Rat1 and Xrn1. Since deletion of MET22 or mutation of RAT1 and XRN1 prevent both degradation and deacylation of mature tRNA(Val(AAC)) in a trm8-Delta trm4-Delta strain and result in healthy growth at 37 degrees C, hypomodified tRNA(Val(AAC)) is at least partially functional and structurally intact under these conditions. The integrity of multiple mature tRNA species is subject to surveillance by the RTD pathway, since mutations in this pathway also prevent degradation of at least three other mature tRNAs lacking other combinations of modifications. The RTD pathway is the first to be implicated in the turnover of mature RNA species from the class of stable RNAs. These results and the results of others demonstrate that tRNA, like mRNA, is subject to multiple quality control steps.	2008

Verma, D. P S . A Rice HAL2-like Gene Encodes a Ca[IMAGE]-sensitive 3`(2`),5`-Diphosphonucleoside 3`(2`)-Phosphohydrolase and Complements Yeast met22 and Escherichia coli cysQ Mutations[J]. Journal of Biological Chemistry, 1995, 270(49):29105-29110. Ghaemmaghami S , Huh W K , Bower K , et al. Global analysis of protein expression in yeast[J]. Nature, 2003, 425(6959):737-741.