Gene Ontology annotation through association of InterPro records with GO terms
Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity
Annotation inferences using phylogenetic trees
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Electronic Gene Ontology annotations created by ARBA machine learning models
Combined Automated Annotation using Multiple IEA Methods
ORFeome cloning and global analysis of protein localization in the fission yeast Schizosaccharomyces pombe.
Division of labour: tRNA methylation by the NSun2 tRNA methyltransferases Trm4a and Trm4b in fission yeast.
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Trm4b does not carry out physiological tRNA wobble C34 methylation.
"Trm4b methylates both C34 and C49 in vitro, even though it does not methylate C34 in vivo."
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Trm4a and Trm4b arose by a recent duplication specific to the S. pombe lineage.
"they derive from a relatively recent duplication event that occurred independently of the duplication in plants"
UniProtKB O13935: curated sequence, features and source attribution
Pmt1, a Dnmt2 homolog in Schizosaccharomyces pombe, mediates tRNA methylation in response to nutrient signaling.
Falcon research on Trm4b/O13935 tRNA methylation
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The biochemical and genetic assignments must distinguish in-vitro from physiological C34 activity.
"It does **not** overturn the in-vivo assignment of C34 to Trm4a."
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Nuclear evidence does not refute a cytoplasmic pool.
"This conclusion does not exclude transient cytoplasmic residence or modification of recycled tRNAs"
OpenScientist investigation of Trm4b rRNA, mRNA and mitochondrial ribosome functions
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The rRNA methyltransferase, rRNA-processing and mitochondrial ribosome assembly IBAs are NSUN4 paralog carry-over within heterogeneous PTHR22808.
"Trm4b (O13935), **NSUN2** (human Q08J23 / mouse Q1HFZ0), **and NSUN4** (human Q96CB9 / mouse Q9CZ57) all map to **PTHR22808**"
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The mRNA methyltransferase ISS is plausible but non-core and experimentally untested in fission yeast.
"The only non-tRNA function with a defensible rationale is **mRNA (cytidine-5-)-methyltransferase (GO:0062152)**, which sits on Trm4b as an **ISS projection from human NSUN2 (Q08J23)**."