The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.
You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.
We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.
We are interested in where in or outside the cell the gene product carries out its function.
We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.
Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.
Target identity (user-provided UniProt context): UniProt Q9Y6Z9 is annotated as “Sorbose reductase sou1” (EC 1.1.1.289) / “Sorbitol utilization protein sou1”, belonging to the short-chain dehydrogenases/reductases (SDR) family.
What the retrieved S. pombe literature supports directly: the gene symbol sou1 is indeed used for an S. pombe transcript in peer-reviewed work (measured by microarray/Northern blot in a transcription study) (lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 9-10). However, in the retrieved corpus no paper explicitly connects the symbol “sou1” to the systematic ID SPAC8E11.10 or UniProt Q9Y6Z9, and no direct enzymology/localization experiments for the S. pombe protein were retrieved (lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 9-10).
Ambiguity warning: “SOU1/sou1” is also used in other fungi (notably Candida albicans), where it clearly denotes a sorbose-utilization gene encoding an NADPH-dependent L-sorbose reductase; this creates a substantial risk of cross-organism conflation (wang2004roleofthe pages 1-2). Therefore, organism-specific claims below are separated into (i) direct S. pombe evidence vs (ii) comparative context.
Across fungal literature, SOU1 commonly refers to an NADPH-dependent L-sorbose reductase implicated in sorbose utilization; in C. albicans this is experimentally described as “NADPH-dependent L-sorbose reductase” and is transcriptionally regulated in connection with the ability to grow on L-sorbose (wang2004roleofthe pages 1-2). Comparative genomics literature also explicitly defines SOU1 (EC 1.1.1.289) as converting L-sorbose → D-sorbitol (lopes2016genomicanalysisand pages 1-2). These statements are consistent with (but do not experimentally validate) the UniProt annotation for S. pombe Q9Y6Z9.
SDR enzymes are a large superfamily of NAD(P)(H)-dependent oxidoreductases; in the S. pombe environmental stress response study, sorbitol stress induces multiple genes encoding putative sugar oxidoreductases and a “hydrolase short chain dehydrogenase,” indicating that oxidoreductase capacity is part of the osmotic/sorbitol response program in fission yeast (chen2003globaltranscriptionalresponses pages 8-9). This supports a plausible functional neighborhood for an SDR-annotated “sou1”, but it is not gene-specific evidence.
No direct experimental evidence for the enzymatic reaction, substrate specificity, kinetics, or cofactor preference of the S. pombe Sou1 protein was identified in the retrieved full texts. In particular, none of the retrieved S. pombe papers provides an enzymatic assay or purified-protein characterization for “sou1” (lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 9-10).
What is supported is that sou1 is transcriptionally responsive in contexts linked to cell-cycle/cell-separation transcriptional programs. Lee et al. (2005) report that eng1, mid2, and sou1 transcripts decreased in TFIIH-associated kinase (Mcs6/Pmh1) mutant backgrounds during restrictive conditions, as part of a broader defect in transcribing a cell-cycle-regulated gene cluster (publication date: Jun 2005; URL: https://doi.org/10.1091/mbc.e04-11-0982) (lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 9-10).
Chen et al. (2003) profiled global transcriptional responses of S. pombe to environmental stresses and reported that sorbitol exposure produced a distinct transcriptional signature including “sorbitol-specific genes”; among these were genes annotated as putative sugar oxidoreductases that “may be involved in sorbitol utilization,” as well as a gene encoding a “hydrolase short chain dehydrogenase” (publication date: Jan 2003; URL: https://doi.org/10.1091/mbc.e02-08-0499) (chen2003globaltranscriptionalresponses pages 8-9). The same work highlights that the Sty1 MAPK pathway is important for sorbitol stress gene expression in S. pombe (chen2003globaltranscriptionalresponses pages 11-13).
Important limitation: Chen et al. do not name sou1 (or SPAC8E11.10) in the quoted sections; thus, these data provide contextual support for polyol/oxidoreductase biology under sorbitol stress, not direct evidence about Sou1 itself (chen2003globaltranscriptionalresponses pages 8-9).
No subcellular localization measurements (tagging microscopy, fractionation, or organelle assignment) for S. pombe Sou1 were found in the retrieved texts (lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 9-10).
Within the documents retrieved in this run, no 2023–2024 primary studies were found that explicitly mention S. pombe sou1 / SPAC8E11.10 / UniProt Q9Y6Z9 or that provide new functional/structural characterization. As a result, the “latest research” component for this specific gene is currently evidence-limited in the accessible corpus.
A relevant methodological development (indirect) is the increasing use of large-scale genotype–phenotype datasets and machine learning to infer yeast sugar-utilization pathways; for example, Harrison et al. (Apr 2024) used genomic/metabolic/ecological data across >1,000 yeast species to identify an alternative galactose utilization pathway, and notes that S. pombe uses galactose in glycosylation but not for assimilation (https://doi.org/10.1073/pnas.2315314121) (not directly about sou1) (paper retrieved but not cited in evidence snippets in this run).
Because gene-specific S. pombe Sou1 function was not directly evidenced here, applications are best stated at the enzyme-class / ortholog level:
Quantitative values directly tied to S. pombe sou1 were not retrieved (e.g., no fold-change values for sou1 mRNA, no enzyme kinetics, no growth curves for a sou1 deletion/overexpression).
The most concrete quantitative-style information in the current evidence set includes:
| Claim/annotation | Evidence type | Key details/quantitative data | Source with year and DOI/URL if available | Notes/limitations about gene identity specificity |
|---|---|---|---|---|
| sou1 is a bona fide S. pombe gene/transcript name in the literature | Indirect mention in primary experiment | In a study of TFIIH-associated kinase function in S. pombe, sou1 transcript levels were analyzed alongside ace2, eng1, mid2; the authors report that eng1, mid2, and sou1 transcripts decreased in the mutant background, indicating that sou1 is an annotated S. pombe transcript/gene name. No enzyme function was provided. (lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 10-11, lee2005impairmentofthe pages 9-10) | Lee et al., 2005, Molecular Biology of the Cell; DOI: 10.1091/mbc.e04-11-0982; URL: https://doi.org/10.1091/mbc.e04-11-0982 | This supports gene-name existence in S. pombe, but does not explicitly link the transcript to SPAC8E11.10 or UniProt Q9Y6Z9 within the paper text. |
| Osmotic/sorbitol stress in S. pombe induces genes predicted to participate in sorbitol utilization, including oxidoreductases | Primary experiment, but not sou1-specific | Microarray analysis under sorbitol stress identified 13 sorbitol-specific genes and 8 CESR genes super-induced by sorbitol. Among the sorbitol-specific genes, SPAC22A12.17c and SPACUNK4.17 were described as putative sugar oxidoreductases that may be involved in sorbitol utilization; SPAC25B8.12c encoded a hydrolase short-chain dehydrogenase. (chen2003globaltranscriptionalresponses pages 8-9, chen2003globaltranscriptionalresponses pages 11-13, chen2003globaltranscriptionalresponses pages 9-11) | Chen et al., 2003, Molecular Biology of the Cell; DOI: 10.1091/mbc.e02-08-0499; URL: https://doi.org/10.1091/mbc.e02-08-0499 | Important contextual support for a sorbitol-related metabolic program in S. pombe, but the paper does not explicitly name sou1/SPAC8E11.10/Q9Y6Z9. Therefore this is indirect evidence only. |
| The specific annotation of S. pombe Sou1 as “sorbose reductase / sorbitol utilization protein” is not directly demonstrated in the retrieved primary S. pombe papers | Inference from absence of explicit evidence | Across the retrieved S. pombe papers, no direct enzymatic assay, no substrate panel, no kinetic constants, and no localization data were found for sou1/SPAC8E11.10/Q9Y6Z9. (chen2003globaltranscriptionalresponses pages 8-9, chen2003globaltranscriptionalresponses pages 11-13, chen2003globaltranscriptionalresponses pages 9-11, lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 10-11, lee2005impairmentofthe pages 9-10) | Synthesized from retrieved S. pombe contexts | This is the key limitation: current context supports very limited organism-specific functional annotation. The UniProt/PomBase-style assignment cannot be fully validated from the gathered primary literature alone. |
| A homologously named SOU1 in Candida albicans encodes an NADPH-dependent L-sorbose reductase | Primary experiment in a different organism | The C. albicans SOU1 gene was described as encoding NADPH-dependent L-sorbose reductase and its transcription increased in sorbose-utilizing mutants; BMH1 was reported to repress SOU1 transcription. (wang2004roleofthe pages 1-2, wang2004roleofthe pages 7-9) | Wang et al., 2004, Yeast; DOI: 10.1002/yea.1079; URL: https://doi.org/10.1002/yea.1079 | Do not treat as direct evidence for S. pombe sou1. Useful only as comparative context showing that the symbol SOU1/sou1 is ambiguous across fungi and commonly associated with sorbose reduction. |
| Comparative genomics literature outside S. pombe links SOU1 to EC 1.1.1.289 and L-sorbose to D-sorbitol conversion | Indirect mention / comparative genomics | A yeast comparative genomics paper notes that SOU1 (K17742; EC 1.1.1.289) is an enzyme that converts L-sorbose into D-sorbitol. (lopes2016genomicanalysisand pages 1-2) | Lopes et al., 2016, FEMS Yeast Research; DOI: 10.1093/femsyr/fow044; URL: https://doi.org/10.1093/femsyr/fow044 | Again, this is not S. pombe-specific experimental evidence for SPAC8E11.10/Q9Y6Z9; it is consistent with the UniProt annotation but remains indirect. |
| No subcellular localization evidence for S. pombe Sou1 was identified in current context | Inference from absence of evidence | No microscopy, fractionation, localization tag, or compartment-specific functional data were found for S. pombe sou1 in the retrieved contexts. (chen2003globaltranscriptionalresponses pages 8-9, chen2003globaltranscriptionalresponses pages 11-13, chen2003globaltranscriptionalresponses pages 9-11, lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 10-11, lee2005impairmentofthe pages 9-10) | Synthesized from retrieved S. pombe contexts | Localization therefore remains unresolved from the current evidence set; any cytosolic assignment would be a family-based inference, not directly demonstrated here. |
| No quantitative enzyme kinetics or substrate-specificity data for S. pombe Sou1 were identified in current context | Inference from absence of evidence | No Km, Vmax, cofactor preference measurements, or direct substrate-conversion assays were retrieved for S. pombe sou1/SPAC8E11.10/Q9Y6Z9. (chen2003globaltranscriptionalresponses pages 8-9, chen2003globaltranscriptionalresponses pages 11-13, chen2003globaltranscriptionalresponses pages 9-11, lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 10-11, lee2005impairmentofthe pages 9-10) | Synthesized from retrieved S. pombe contexts | This is a major evidence gap relative to the requested functional annotation. The strongest reaction assignment in current context comes only from non-pombe SOU1 literature and comparative annotation. |
Table: This table summarizes the currently supported evidence for Schizosaccharomyces pombe sou1 from the retrieved context, separating direct organism-specific findings from indirect comparative inferences. It highlights that most strong functional claims for Sou1 remain indirect rather than experimentally demonstrated in S. pombe.
Key conclusion: In the currently retrieved and machine-read full-text evidence, S. pombe sou1 is confirmed as a gene/transcript name studied at the expression level, and the organism has an osmotic/sorbitol stress transcriptional program enriched for oxidoreductases/SDRs; however, direct functional annotation of the Sou1 protein encoded by SPAC8E11.10 / UniProt Q9Y6Z9 (reaction, substrates, localization) could not be verified from primary S. pombe literature retrieved here (chen2003globaltranscriptionalresponses pages 8-9, lee2005impairmentofthe pages 8-9, lee2005impairmentofthe pages 9-10). Comparative fungal literature strongly supports that “SOU1” commonly denotes an NADPH-dependent L-sorbose reductase mediating L-sorbose → D-sorbitol, but those data are not organism- or accession-specific to S. pombe Q9Y6Z9 (lopes2016genomicanalysisand pages 1-2, wang2004roleofthe pages 1-2).
References
(lee2005impairmentofthe pages 8-9): Karen M. Lee, Ida Miklos, Hongyan Du, Stephen Watt, Zsolt Szilagyi, Julia E. Saiz, Ram Madabhushi, Christopher J. Penkett, Matthias Sipiczki, Jürg Bähler, and Robert P. Fisher. Impairment of the tfiih-associated cdk-activating kinase selectively affects cell cycle-regulated gene expression in fission yeast. Molecular biology of the cell, 16 6:2734-45, Jun 2005. URL: https://doi.org/10.1091/mbc.e04-11-0982, doi:10.1091/mbc.e04-11-0982. This article has 71 citations and is from a domain leading peer-reviewed journal.
(lee2005impairmentofthe pages 9-10): Karen M. Lee, Ida Miklos, Hongyan Du, Stephen Watt, Zsolt Szilagyi, Julia E. Saiz, Ram Madabhushi, Christopher J. Penkett, Matthias Sipiczki, Jürg Bähler, and Robert P. Fisher. Impairment of the tfiih-associated cdk-activating kinase selectively affects cell cycle-regulated gene expression in fission yeast. Molecular biology of the cell, 16 6:2734-45, Jun 2005. URL: https://doi.org/10.1091/mbc.e04-11-0982, doi:10.1091/mbc.e04-11-0982. This article has 71 citations and is from a domain leading peer-reviewed journal.
(wang2004roleofthe pages 1-2): Ying‐Kai Wang, Biswadip Das, David H. Huber, Melanie Wellington, M. Anaul Kabir, Fred Sherman, and Elena Rustchenko. Role of the 14–3–3 protein in carbon metabolism of the pathogenic yeast candida albicans. Yeast, 21:685-702, Jun 2004. URL: https://doi.org/10.1002/yea.1079, doi:10.1002/yea.1079. This article has 32 citations and is from a peer-reviewed journal.
(lopes2016genomicanalysisand pages 1-2): Mariana R. Lopes, Camila G. Morais, Jacek Kominek, R. M. Cadete, M. A. Soares, A. Uetanabaro, C. Fonseca, M. Lachance, C. T. Hittinger, and C. Rosa. Genomic analysis and d-xylose fermentation of three novel spathaspora species: spathaspora girioi sp. nov., spathaspora hagerdaliae f. a., sp. nov. and spathaspora gorwiae f. a., sp. nov. FEMS yeast research, Jun 2016. URL: https://doi.org/10.1093/femsyr/fow044, doi:10.1093/femsyr/fow044. This article has 46 citations and is from a peer-reviewed journal.
(chen2003globaltranscriptionalresponses pages 8-9): Dongrong Chen, W. Mark Toone, Juan Mata, Rachel Lyne, Gavin Burns, Katja Kivinen, Alvis Brazma, Nic Jones, and Jürg Bähler. Global transcriptional responses of fission yeast to environmental stress. Molecular biology of the cell, 14 1:214-29, Jan 2003. URL: https://doi.org/10.1091/mbc.e02-08-0499, doi:10.1091/mbc.e02-08-0499. This article has 978 citations and is from a domain leading peer-reviewed journal.
(chen2003globaltranscriptionalresponses pages 11-13): Dongrong Chen, W. Mark Toone, Juan Mata, Rachel Lyne, Gavin Burns, Katja Kivinen, Alvis Brazma, Nic Jones, and Jürg Bähler. Global transcriptional responses of fission yeast to environmental stress. Molecular biology of the cell, 14 1:214-29, Jan 2003. URL: https://doi.org/10.1091/mbc.e02-08-0499, doi:10.1091/mbc.e02-08-0499. This article has 978 citations and is from a domain leading peer-reviewed journal.
(lee2005impairmentofthe pages 10-11): Karen M. Lee, Ida Miklos, Hongyan Du, Stephen Watt, Zsolt Szilagyi, Julia E. Saiz, Ram Madabhushi, Christopher J. Penkett, Matthias Sipiczki, Jürg Bähler, and Robert P. Fisher. Impairment of the tfiih-associated cdk-activating kinase selectively affects cell cycle-regulated gene expression in fission yeast. Molecular biology of the cell, 16 6:2734-45, Jun 2005. URL: https://doi.org/10.1091/mbc.e04-11-0982, doi:10.1091/mbc.e04-11-0982. This article has 71 citations and is from a domain leading peer-reviewed journal.
(chen2003globaltranscriptionalresponses pages 9-11): Dongrong Chen, W. Mark Toone, Juan Mata, Rachel Lyne, Gavin Burns, Katja Kivinen, Alvis Brazma, Nic Jones, and Jürg Bähler. Global transcriptional responses of fission yeast to environmental stress. Molecular biology of the cell, 14 1:214-29, Jan 2003. URL: https://doi.org/10.1091/mbc.e02-08-0499, doi:10.1091/mbc.e02-08-0499. This article has 978 citations and is from a domain leading peer-reviewed journal.
(wang2004roleofthe pages 7-9): Ying‐Kai Wang, Biswadip Das, David H. Huber, Melanie Wellington, M. Anaul Kabir, Fred Sherman, and Elena Rustchenko. Role of the 14–3–3 protein in carbon metabolism of the pathogenic yeast candida albicans. Yeast, 21:685-702, Jun 2004. URL: https://doi.org/10.1002/yea.1079, doi:10.1002/yea.1079. This article has 32 citations and is from a peer-reviewed journal.