The predicted name is a correct domain description and does not assert phosphatase catalysis. The main uncertainty is localization of the exact product: its altered N-terminus carries a computational signal-peptide call, while the characterized MTMR12-MTM1 mechanism acts in the cytoplasm and at muscle membranes.
A0A8I5ZMD5 and Q5FVM6 are same-gene rat Mtmr12 products. Selected residues 41–732 align to reference 57–748 with 691/692 identities; the entire 439-residue myotubularin phosphatase domain is identical. The first 40 selected residues differ from the reference N-terminus. SignalP annotates residues 1–20 as a signal peptide, but this is a prediction rather than demonstrated ER import.
MTMR12 primarily regulates the function of myotubularin protein by affecting protein levels instead of modulating the enzymatic activity
the catalytically inactive MTMR12 only partially but significantly rescues myotubularin function
The complete emitted record is preserved in Mtmr12-protnlm-source.json. Assessments below address the selected protein product; evidence on longer products is identified explicitly.
Myotubularin phosphatase domain-containing protein
CNN (CS 2). The complete myotubularin phosphatase domain is retained, including identity across the reference domain. The wording “domain-containing” does not claim autonomous phosphatase activity and should not be scored as pseudoenzyme overannotation. Sequence comparison.
Membrane
UNC (CS 1). Membrane association is plausible through the normal MTM1 complex and independently through a possible altered trafficking route, but neither demonstrates stable membrane association of this product. A cleavable signal-peptide prediction also does not by itself establish that the mature protein remains membrane bound. PMID:23818870(https://pubmed.ncbi.nlm.nih.gov/23818870/); exact record.
All 1 emitted GO claims are individually assessed in Mtmr12-protnlm-predictions-review.yaml.
The myotubularin family includes active phosphatases and inactive binding partners. MTMR12 belongs to the latter functional class; the full domain’s preservation does not reinstate MTM1-like catalysis. The sequence distinction here concerns the N-terminus and potentially trafficking, not loss of the phosphatase fold.
The primary report has full text and assays zebrafish, mammalian cells and muscle, rather than this alternative rat protein product. The genuine Falcon report provides a useful family and MTM1-interaction synthesis, but its broad localization transfer needs the exact N-terminal caveat. A signal-peptide predictor is insufficient to overturn the established gene-level mechanism or to declare a secreted isoform.
Exact sequence mapping: Mtmr12-bioinformatics/RESULTS.md. Global alignments can place nonhomologous alternative tails opposite gaps or distant residues; only conserved segments and explicitly retained feature intervals support functional transfer.