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this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.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.
The supplied identifiers are mutually consistent: sen15, systematic ORF SPAC959.10, UniProt Q7LKV3, from Schizosaccharomyces pombe strain 972/ATCC 24843, denotes a probable fungal Sen15-family tRNA-splicing-endonuclease subunit. Its Sen15_fungi, tRNA-endonuclease-Sen15, and endonuclease-like domain assignments agree with that identity. No evidence was found that the symbol refers here to a different protein.
However, literature specifically characterizing Q7LKV3/SPAC959.10 is extremely limited. The defensible annotation is therefore that Q7LKV3 is the predicted S. pombe ortholog of Sen15, a principally non-catalytic architectural subunit of the heterotetrameric eukaryotic tRNA-splicing endonuclease. Direct biochemical activity, physical interactions, phenotype, abundance, and intracellular localization have not been demonstrated for Q7LKV3 in the literature retrieved. Mechanistic statements below are accordingly labeled as conserved inference rather than direct S. pombe evidence.
| Annotation claim | Best evidence | Source organism/system | Evidence status for Q7LKV3 | Caveat |
|---|---|---|---|---|
| Identity: sen15, ORF SPAC959.10, UniProt Q7LKV3; probable tRNA-splicing endonuclease subunit Sen15 | UniProt identity supplied for the specified target | Schizosaccharomyces pombe strain 972 / ATCC 24843 | Direct database identity | No Q7LKV3-specific primary study was recovered; the functional qualifier remains “probable.” |
| Sen15-family protein with Sen15_fungi, tRNA-endonuclease Sen15, and related endonuclease-like domains | InterPro/Pfam domain assignments supplied with the target; these agree with conserved Sen15/TSEN15 architecture | S. pombe sequence plus comparative domain models | Direct database identity | Domain membership supports orthology and complex function but does not demonstrate catalytic activity or localization. |
| Member of a four-subunit eukaryotic tRNA-splicing endonuclease | Human TSEN comprises TSEN2, TSEN34, TSEN54, and TSEN15; the four recombinant subunits are sufficient for cleavage at both splice sites (sekulovski2023structuralbasisof pages 1-4, sekulovski2023structuralbasisof pages 4-7) | Human recombinant TSEN and cryo-EM complexes | Strong conserved inference | Four-subunit membership has not been biochemically demonstrated for Q7LKV3 in the recovered literature. |
| Sen15 is principally a non-catalytic architectural/assembly subunit | Human TSEN15 is classified as structural and showed no detectable direct pre-tRNA contact in one cryo-EM structure (sekulovski2023structuralbasisof pages 1-4, sekulovski2023structuralbasisof pages 4-7) | Human TSEN | Strong conserved inference | Absence of observed RNA contact does not exclude transient or indirect contributions; Q7LKV3 itself has not been assayed. |
| Sen15 cooperates with or structurally supports Sen34 | Comparative literature describes yeast Sen15 as cooperating with Sen34 in functional multimerization; a human TSEN15–TSEN34 heterodimer preserves archaeal-like interactions (soma2013identificationofhighlydisrupted pages 5-6, sekulovski2023structuralbasisof pages 1-4) | Unspecified yeast literature and human structural studies | Strong conserved inference | The yeast passage does not identify S. pombe, and a direct Q7LKV3–Sen34 interaction has not been reported. |
| Sen15 is not assigned either splice-site catalytic reaction | Catalysis maps to Sen2/TSEN2 and Sen34/TSEN34, whereas Sen15 and Sen54 are non-catalytic subunits (sekulovski2023structuralbasisof pages 1-4, meineke2012insightsintoanticodon pages 38-42) | Yeast comparative genetics and human TSEN | Strong conserved inference | Catalytic inactivity of purified Q7LKV3 has not been tested directly. |
| Sen2 cleaves the 5′ splice site and Sen34 cleaves the 3′ splice site | Conserved Tyr/His/Lys catalytic centers and subunit-specific cleavage assignments are supported by genetic and structural data (sekulovski2023structuralbasisof pages 1-4, sekulovski2023structuralbasisof pages 7-9, meineke2012insightsintoanticodon pages 38-42) | Yeast and human TSEN | Strong conserved inference | This assigns catalysis within the predicted S. pombe complex, not to Sen15 itself. |
| Complex substrate: intron-containing nuclear pre-tRNAs | Eukaryotic TSEN excises intronic sequences from pre-tRNAs; human structures used pre-tRNA^Tyr and pre-tRNA^Arg and resolved bulge–helix splice-site recognition (sekulovski2023structuralbasisof pages 1-4, sekulovski2023structuralbasisof pages 4-7) | Human TSEN–pre-tRNA cryo-EM complexes | Strong conserved inference | No individual S. pombe pre-tRNA substrates or Q7LKV3-dependent cleavage kinetics were identified. |
| Cleavage products carry a 2′,3′-cyclic phosphate on the 5′ exon and a 5′-OH on the 3′ exon | Established chemistry of eukaryotic tRNA-splicing endonuclease cleavage (hopper2010cellulardynamicsof pages 3-3) | General eukaryotic/yeast tRNA-splicing pathway | Strong conserved inference | This is the reaction of the assembled endonuclease; Sen15 does not itself supply the catalytic centers. |
| Biological pathway: endonucleolytic step of tRNA intron removal, followed by exon ligation and end repair | Endonuclease cleavage initiates tRNA splicing; ligase and 2′-phosphotransferase subsequently complete repair (hopper2010cellulardynamicsof pages 3-3) | Eukaryotic tRNA maturation | Strong conserved inference | Direct epistasis or pathway analysis for S. pombe sen15/Q7LKV3 was not recovered. |
| Cellular localization in S. pombe | No direct Q7LKV3 localization evidence was found | S. pombe | Unsupported | Budding-yeast Sen subunits occur on the cytoplasmic mitochondrial surface, whereas vertebrate TSEN is nuclear; this lineage variation makes transfer to fission yeast unsafe (hopper2010cellulardynamicsof pages 3-3, yoshihisa2014handlingtrnaintrons pages 7-8). |
| Recent structural advance: 2023 cryo-EM resolved TSEN assembly, substrate positioning, and catalytic architecture | Independent human TSEN studies reported 3.8 Å and 3.1 Å reconstructions and showed TSEN15 as structural rather than a major RNA-contacting subunit (hayne2023structuralbasisfor pages 1-2, sekulovski2023structuralbasisof pages 4-7) | Human recombinant TSEN–pre-tRNA complexes | Strong conserved inference | These are mechanistically informative ortholog studies, not structures of Q7LKV3 or the S. pombe complex. |
| Direct biochemical, interaction, phenotype, or localization characterization of Q7LKV3 | No specific study was recovered for Q7LKV3/SPAC959.10 | S. pombe | Unsupported | The most defensible annotation is therefore domain- and orthology-based: a probable non-catalytic Sen15-family component of the pre-tRNA splicing endonuclease. |
Table: Evidence-tier assessment of functional claims for S. pombe sen15/Q7LKV3, separating direct database identity from conserved mechanistic inference and unsupported organism-specific assertions.
Eukaryotic tRNA-splicing endonuclease is generally a four-subunit assembly comprising Sen2/TSEN2, Sen34/TSEN34, Sen54/TSEN54, and Sen15/TSEN15. Human recombinant complexes containing these four proteins are sufficient for cleavage at both pre-tRNA splice sites. Recent structural work classifies TSEN2 and TSEN34 as catalytic and TSEN15 and TSEN54 as structural subunits. This architecture strongly supports assignment of S. pombe Q7LKV3 to the non-catalytic Sen15 position in the corresponding fungal complex. (sekulovski2023structuralbasisof pages 1-4, hayne2023structuralbasisfor pages 1-2, sekulovski2023structuralbasisof pages 4-7)
Sen15’s most likely primary function is to stabilize or organize the catalytic assembly, especially the Sen34-containing half. Comparative literature describes yeast Sen15 as cooperating with Sen34 in functional multimerization, while structural work has demonstrated an archaeal-like TSEN15–TSEN34 interface in the human complex. One human disease-associated TSEN15 interface substitution, H116Y, destabilized the complex by approximately 3.0 °C, illustrating how Sen15 can affect assembly without supplying a catalytic center. These observations support—but do not directly prove—a Q7LKV3–Sen34 architectural relationship in fission yeast. (sekulovski2023structuralbasisof pages 7-9, soma2013identificationofhighlydisrupted pages 5-6, sekulovski2023structuralbasisof pages 1-4)
A 2023 cryo-EM study detected no direct pre-tRNA contact by human TSEN15, whereas TSEN54, TSEN34, and TSEN2 made substantial RNA contacts. TSEN15 should consequently not be annotated as the principal substrate-recognition or catalytic subunit. It may instead support catalytic-subunit geometry, RNA orientation near a splice site, assembly stability, or product handling. Some of these finer roles remain hypotheses even in the human system. (hayne2023structuralbasisfor pages 6-7, sekulovski2023structuralbasisof pages 4-7, hayne2023structuralbasisfor pages 4-6)
The assembled endonuclease catalyzes two phosphodiester-bond cleavages at the exon–intron boundaries of an intron-containing precursor tRNA:
intron-containing pre-tRNA → 5′ tRNA exon bearing a 2′,3′-cyclic phosphate + excised intron + 3′ tRNA exon bearing a 5′-OH.
Subsequent ligase and 2′-phosphotransferase reactions join and repair the exons to produce mature tRNA. Thus, sen15 functions in the endonucleolytic first stage of nuclear-encoded tRNA intron removal, upstream of exon ligation and final end repair. (hopper2010cellulardynamicsof pages 3-3)
The conserved catalytic division of labor assigns the 5′ splice-site cut to Sen2 and the 3′ splice-site cut to Sen34. Catalytic Tyr/His/Lys arrangements in these subunits mediate RNA transesterification; for the human TSEN34 site, structural analysis places Y247 to activate the attacking 2′-OH, H255 to protonate the leaving 5′ oxygen, and K286 to stabilize negative charge. Q7LKV3 itself is therefore not predicted to catalyze either cleavage. (sekulovski2023structuralbasisof pages 1-4, sekulovski2023structuralbasisof pages 7-9, meineke2012insightsintoanticodon pages 38-42)
The physiological substrate class is intron-containing pre-tRNA, not mature tRNA, mRNA, or a free RNA intron. Eukaryotic TSEN recognizes the folded tRNA body together with splice-junction geometry in the anticodon region. Human cryo-EM complexes with pre-tRNA^Tyr and pre-tRNA^Arg resolved a three-nucleotide bulge at the 3′ splice site and extensive positioning by TSEN34 and TSEN54. The mature tRNA body serves as an architectural reference, while catalytic subunits inspect the splice-junction RNA. (sekulovski2023structuralbasisof pages 1-4, hayne2023structuralbasisfor pages 1-2, sekulovski2023structuralbasisof pages 4-7)
The recent human structures were obtained at 3.8 Å for full-length TSEN–pre-tRNA^Tyr and 3.1 Å for a truncated TSEN–pre-tRNA^Arg complex. TSEN34/TSEN54 contacted the mature tRNA body over approximately 1,838.3 Ų, and their protein–protein interface covered approximately 2,287.2 Ų. These quantitative results underscore that substrate recognition is distributed across the assembled complex rather than being an intrinsic RNA-binding activity of Sen15. (sekulovski2023structuralbasisof pages 4-7)
No study retrieved identified which individual S. pombe intron-containing tRNAs depend on Q7LKV3, measured cleavage kinetics, or tested sequence preferences. It is therefore inappropriate to assign a specific tRNA isoacceptor to Sen15. The likely specificity is the collective specificity of the S. pombe Sen complex for structurally mature, intron-containing pre-tRNAs.
The immediate pathway is tRNA maturation/tRNA intron splicing, which supplies functional tRNAs for cytoplasmic translation. Sen15’s contribution is indirect but essential to reaction architecture: it enables productive assembly or geometry of the endonuclease rather than performing covalent chemistry itself. Comparative yeast literature calls Sen15 important for functional multimerization, although the cited passage does not specify S. pombe. (soma2013identificationofhighlydisrupted pages 5-6)
Broader effects on translation, growth, stress responses, or RNA homeostasis would be expected if the complex failed, because unspliced pre-tRNAs would accumulate and mature tRNA production could decline. Nevertheless, no Q7LKV3-specific perturbation study was recovered, so such outcomes should be treated as pathway-level predictions—not demonstrated phenotypes of S. pombe sen15.
The localization of Q7LKV3 in S. pombe is unresolved from the available evidence. This is important because tRNA-splicing localization varies markedly among eukaryotes. In Saccharomyces cerevisiae, Sen-complex subunits localize on the cytoplasmic face of mitochondria, whereas vertebrate TSEN is nuclear. Moreover, experimentally relocating all budding-yeast Sen subunits to the nucleus still permits pre-tRNA splicing, showing that mitochondrial-surface localization is not chemically required for cleavage, although relocation affects growth and rRNA maturation. (hopper2010cellulardynamicsof pages 3-3, yoshihisa2014handlingtrnaintrons pages 7-8)
Accordingly, the budding-yeast mitochondrial-surface result must not be presented as established for fission yeast. A safe annotation is “intracellular component of the tRNA-splicing machinery; precise S. pombe compartment unknown.” Direct GFP tagging, biochemical fractionation, or proximity-labeling of Q7LKV3 would be required to resolve this point.
The supplied Sen15_fungi and tRNA-endonuclease-Sen15 domain assignments align with the conserved eukaryotic Sen15/TSEN15 lineage. Eukaryotic complexes are evolutionarily related to archaeal tRNA-splicing endonucleases, but eukaryotes distribute catalytic and structural functions among four differentiated proteins. Sen15 and Sen54 are the non-catalytic partners, while Sen2 and Sen34 retain the catalytic centers. (hayne2023structuralbasisfor pages 1-2, hopper2010cellulardynamicsof pages 3-3, meineke2012insightsintoanticodon pages 38-42)
This domain/family agreement makes the functional annotation considerably stronger than an ORF-name match alone. It does not, however, establish localization, essentiality, physical interaction partners, or substrate kinetics for Q7LKV3.
Two independent 2023 structural studies transformed understanding of eukaryotic TSEN by visualizing human heterotetramers bound to intron-containing pre-tRNAs. They established how the mature tRNA body, splice-site bulges, catalytic subunits, and structural scaffold cooperate. Importantly for Q7LKV3 annotation, these studies support TSEN15 as an assembly subunit rather than an autonomous nuclease or dominant RNA-binding protein. One study’s molecular-dynamics analysis used five simulations and 5,000 configurations; only 35 of 80 RNA nucleotides maintained complex contacts at least 75% of the time, illustrating a defined rather than indiscriminate RNA interface. (sekulovski2023structuralbasisof pages 4-7, hayne2023structuralbasisfor pages 20-24)
Relevant primary publications are:
A 2024 review, Schultz and Kothe, “RNA modifying enzymes shape tRNA biogenesis and function,” Journal of Biological Chemistry 300:107488, published August 2024, DOI/URL https://doi.org/10.1016/j.jbc.2024.107488, emphasizes the integration of processing, modification, and compartmental trafficking. It does not provide direct Q7LKV3 characterization. No 2023–2024 primary study specifically analyzing S. pombe Sen15 was found.
There is no documented clinical, industrial, or biotechnological implementation specific to Q7LKV3. Its present utility is principally as:
Human TSEN research has medical relevance because TSEN-complex mutations are associated with pontocerebellar hypoplasia, but that disease connection concerns human orthologs and should not be transferred to S. pombe sen15. The human complex has been estimated at only approximately 100 molecules per cell, emphasizing its low abundance and the value of yeast systems for mechanistic experimentation. (sekulovski2023structuralbasisof pages 1-4)
Recommended concise annotation:
Schizosaccharomyces pombe Sen15 (Q7LKV3/SPAC959.10) is a probable non-catalytic Sen15-family subunit of the heterotetrameric tRNA-splicing endonuclease. It is predicted to associate with and structurally support the Sen34-containing catalytic module during recognition and endonucleolytic excision of introns from pre-tRNAs. The assembled complex generates 5′ exons with 2′,3′-cyclic-phosphate ends and 3′ exons with 5′-hydroxyl ends; Sen2 and Sen34, not Sen15, provide the catalytic centers. Its precise localization and organism-specific substrates in fission yeast remain unknown.
Confidence: high for protein identity, family membership, complex class, and non-catalytic architectural role; moderate for the specific Sen34-support relationship in S. pombe; low/unknown for localization, abundance, phenotype, essentiality, and individual tRNA substrates.
The central limitation is the absence of direct Q7LKV3-focused biochemical or cell-biological literature. The report therefore avoids treating human TSEN15 or S. cerevisiae Sen15 observations as if they had been demonstrated in S. pombe.
References
(sekulovski2023structuralbasisof pages 1-4): Samoil Sekulovski, Lukas Sušac, Lukas S. Stelzl, Robert Tampé, and Simon Trowitzsch. Structural basis of substrate recognition by human trna splicing endonuclease tsen. bioRxiv, Sep 2023. URL: https://doi.org/10.1038/s41594-023-00992-y, doi:10.1038/s41594-023-00992-y. This article has 33 citations.
(sekulovski2023structuralbasisof pages 4-7): Samoil Sekulovski, Lukas Sušac, Lukas S. Stelzl, Robert Tampé, and Simon Trowitzsch. Structural basis of substrate recognition by human trna splicing endonuclease tsen. bioRxiv, Sep 2023. URL: https://doi.org/10.1038/s41594-023-00992-y, doi:10.1038/s41594-023-00992-y. This article has 33 citations.
(soma2013identificationofhighlydisrupted pages 5-6): Akiko Soma, Junichi Sugahara, Akinori Onodera, Nozomu Yachie, Akio Kanai, Satoru Watanabe, Hirofumi Yoshikawa, Mio Ohnuma, Haruko Kuroiwa, Tsuneyoshi Kuroiwa, and Yasuhiko Sekine. Identification of highly-disrupted trna genes in nuclear genome of the red alga, cyanidioschyzon merolae 10d. Scientific Reports, Jul 2013. URL: https://doi.org/10.1038/srep02321, doi:10.1038/srep02321. This article has 19 citations and is from a peer-reviewed journal.
(meineke2012insightsintoanticodon pages 38-42): B Meineke. Insights into anticodon nuclease toxicity and rescue by trna repair in vivo. Unknown journal, 2012.
(sekulovski2023structuralbasisof pages 7-9): Samoil Sekulovski, Lukas Sušac, Lukas S. Stelzl, Robert Tampé, and Simon Trowitzsch. Structural basis of substrate recognition by human trna splicing endonuclease tsen. bioRxiv, Sep 2023. URL: https://doi.org/10.1038/s41594-023-00992-y, doi:10.1038/s41594-023-00992-y. This article has 33 citations.
(hopper2010cellulardynamicsof pages 3-3): Anita K. Hopper, Dave A. Pai, and David R. Engelke. Cellular dynamics of trnas and their genes. FEBS letters, Jan 2010. URL: https://doi.org/10.1016/j.febslet.2009.11.053, doi:10.1016/j.febslet.2009.11.053. This article has 89 citations and is from a peer-reviewed journal.
(yoshihisa2014handlingtrnaintrons pages 7-8): Tohru Yoshihisa. Handling trna introns, archaeal way and eukaryotic way. Frontiers in Genetics, Jul 2014. URL: https://doi.org/10.3389/fgene.2014.00213, doi:10.3389/fgene.2014.00213. This article has 145 citations and is from a peer-reviewed journal.
(hayne2023structuralbasisfor pages 1-2): Cassandra K. Hayne, Kevin John U. Butay, Zachary D. Stewart, Juno M. Krahn, Lalith Perera, Jason G. Williams, Robert M. Petrovitch, Leesa J. Deterding, A. Gregory Matera, Mario J. Borgnia, and Robin E. Stanley. Structural basis for pre-trna recognition and processing by the human trna splicing endonuclease complex. bioRxiv, Sep 2023. URL: https://doi.org/10.1038/s41594-023-00991-z, doi:10.1038/s41594-023-00991-z. This article has 38 citations.
(hayne2023structuralbasisfor pages 6-7): Cassandra K. Hayne, Kevin John U. Butay, Zachary D. Stewart, Juno M. Krahn, Lalith Perera, Jason G. Williams, Robert M. Petrovitch, Leesa J. Deterding, A. Gregory Matera, Mario J. Borgnia, and Robin E. Stanley. Structural basis for pre-trna recognition and processing by the human trna splicing endonuclease complex. bioRxiv, Sep 2023. URL: https://doi.org/10.1038/s41594-023-00991-z, doi:10.1038/s41594-023-00991-z. This article has 38 citations.
(hayne2023structuralbasisfor pages 4-6): Cassandra K. Hayne, Kevin John U. Butay, Zachary D. Stewart, Juno M. Krahn, Lalith Perera, Jason G. Williams, Robert M. Petrovitch, Leesa J. Deterding, A. Gregory Matera, Mario J. Borgnia, and Robin E. Stanley. Structural basis for pre-trna recognition and processing by the human trna splicing endonuclease complex. bioRxiv, Sep 2023. URL: https://doi.org/10.1038/s41594-023-00991-z, doi:10.1038/s41594-023-00991-z. This article has 38 citations.
(hayne2023structuralbasisfor pages 20-24): Cassandra K. Hayne, Kevin John U. Butay, Zachary D. Stewart, Juno M. Krahn, Lalith Perera, Jason G. Williams, Robert M. Petrovitch, Leesa J. Deterding, A. Gregory Matera, Mario J. Borgnia, and Robin E. Stanley. Structural basis for pre-trna recognition and processing by the human trna splicing endonuclease complex. bioRxiv, Sep 2023. URL: https://doi.org/10.1038/s41594-023-00991-z, doi:10.1038/s41594-023-00991-z. This article has 38 citations.