COL6A2 research notes

These research notes combine original publication text, proteomic tables, curated interaction records and official product sequences. Default Falcon timed out after 90 seconds; the configured Perplexity Lite fallback returned HTTP 401 insufficient_quota. Manual literature review was used; no provider-generated research report is claimed.

Structural core and exact products

One integrated structural core uses GO:0030020 in the canonical alpha1/alpha2/alpha3 type VI trimer (GO:0005589), at beaded microfibrils (GO:0001527). The current structural-term comment permits extracellular matrix collagens; a proteomic identification is not an isolated force assay. No NEW annotation or extra process is proposed. The current definitions, collagen comment and explicit GO:0005589 is_a GO:0140158 edge are included in the source index. PMID:23869615(https://pubmed.ncbi.nlm.nih.gov/23869615/).

Official P12110 products reconstruct exactly as 2C2 (1,019 aa), 2C2A (918 aa) and 2C2A′ (828 aa). The latter two use the recorded VSP edits and share the first 820 residues; no assembly equivalence is inferred. Authentic original human fibroblast Northern/S1/PCR work establishes the three transcripts and major 2C2 abundance, while incorporation of the shorter forms into triple-helical molecules remains unestablished. Original author-upload indexed Methods and Discussion were read; the normal abstract remains a separate source variant. PMID:1690728(https://pubmed.ncbi.nlm.nih.gov/1690728/), PMID:2551668(https://pubmed.ncbi.nlm.nih.gov/2551668/).

Original transfection work uses endogenous human alpha1/alpha2 in SaOs-2 cells with engineered mouse alpha4 N6–C2. Secreted, co-precipitating disulfide-linked chains support positive collagen association and extracellular secretion. Row 44 refines the generic complex to GO:0140158, since GO:0005589 explicitly requires alpha3 and would misdescribe that particular assembly. Independent canonical-complex rows remain accepted. Figure 9 caption and original indexed Methods/Results were read; no new figure-pixel or universal native alpha4 assembly claim is made. PMID:18400749(https://pubmed.ncbi.nlm.nih.gov/18400749/).

The earlier isolated-chain study tests human F225 major 2C2 in 293 cells. Secreted non-triple-helical alpha2 binds pepsin-collagen VI, with weaker fibronectin/perlecan binding; alpha1 behaves differently. Both chains have positive heparin affinity observations. These results are not transferred to every splice product or converted into a second core/NEW assertion. The listed erratum text remains unrecovered, without an unsupported assertion that it is immaterial. PMID:8168508(https://pubmed.ncbi.nlm.nih.gov/8168508/).

Source-specific binding, membranes and glucose response

Three exact human DISC1/COL6A2 interaction-export records preserve positive Y2H association. Canonical participant ROGIDs reconstruct from official full sequences, but this mapping does not recover the original tested fragment boundaries. The original full paper remains unavailable, and its abstract does not list every partner. No wrong-gene or compartment-only rejection follows. Supported generic binding is retained as non-core under the explicit ClinGen project instruction; the interaction does not establish a new COL6A2 adaptor, cytoskeletal activity or physiological DISC1 pathway. PMID:12812986(https://pubmed.ncbi.nlm.nih.gov/12812986/).

Current HPA text reports supported additional plasma-membrane localization, separately from uncertain cytosol and an overall uncertain summary. No image pixels were inspected. All three current ARBA rules have matching target FunFam condition sets; a mismatching alternative PANTHER branch is not treated as rule failure. Membrane definitions include attached proteins. Original NG2 abstracts support whole-collagen VI surface anchoring, without making alpha2 a transmembrane chain or resolving every product. Membrane-associated rows remain non-core. HPA, PMID:8305732(https://pubmed.ncbi.nlm.nih.gov/8305732/), PMID:9099729(https://pubmed.ncbi.nlm.nih.gov/9099729/).

The rat Col6a2 same-term IEP donor traces to high-glucose connective-tissue cultures, with alpha-chain mRNA increases and collagen VI fibril accumulation. Gene-expression change falls within the actual response-to-glucose definition; it is retained as a contextual response, not glucose sensing or metabolism. Mouse sarcolemma transfer is retained with its exact IDA source and full-source access limit. The current definition includes basement-membrane covering and collagen network, so extracellular identity is not a contradiction. PMID:8494053(https://pubmed.ncbi.nlm.nih.gov/8494053/), PMID:16810681(https://pubmed.ncbi.nlm.nih.gov/16810681/).

Actual proteomic target evidence

Original human-aortic tables identify CO6A2_HUMAN with 4/31/11 unique peptides across NaCl/GuHCl/SDS. Feeder-matrix Table 1 detects alpha2 in human hPSF/ihPSF matrices, while HUES1 is ND; one mouse feeder column is also positive. The colon/liver workbook has the same alpha2 group in two sheets, not two independent experiments. Marrow workbooks are positive in healthy/donor groups with inspected disease-group ND/zero, not universally positive across myeloma cohorts. PMID:20551380(https://pubmed.ncbi.nlm.nih.gov/20551380/), PMID:23658023(https://pubmed.ncbi.nlm.nih.gov/23658023/), PMID:25037231(https://pubmed.ncbi.nlm.nih.gov/25037231/), PMID:28344315(https://pubmed.ncbi.nlm.nih.gov/28344315/).

Authentic original atrial HTML/Table 1 detects alpha2(VI) in GuHCl input and glycopeptides, with glycoprotein enrichment blank. Cell-derived ECM Table 1 groups COL6A1/2/3, rather than individually quantifying each chain. Tissue-proteomics Methods were read, but its supplemental workbook responses remain HTML challenges. Vein Figure 3 text names alpha1/alpha3 rather than an inspected alpha2 row. Those two exact target links remain UNVERIFIED in reference assessments without negating independently established matrix biology. PMID:27559042(https://pubmed.ncbi.nlm.nih.gov/27559042/), PMID:28327460(https://pubmed.ncbi.nlm.nih.gov/28327460/), PMID:28675934(https://pubmed.ncbi.nlm.nih.gov/28675934/), PMID:27068509(https://pubmed.ncbi.nlm.nih.gov/27068509/).

Original ACS salivary supplementary tables identify COL6A2. Table S2 row 334 reports five sequences/five spectra/5% coverage. Table S1 rows 4116–4120 contain four distinct sequences across five entries; the major-product C-terminal peptide maps to canonical 994 and is absent from the shorter products. Retain fraction detection as non-core; this does not show every product in exosomes or a vesicle function. Actual single-donor collection/MS and contamination discussion were read. Failed earlier nominal-XLS responses remain excluded HTML. PMID:19199708(https://pubmed.ncbi.nlm.nih.gov/19199708/).

For human CSF, the original public PXD000608 MaxQuant output was genuinely recovered. ProteinGroups physical row 855 identifies the alpha2 group with all three product IDs, ten peptides in each EV pool and low soluble-fraction signal. Parameters specify 1% peptide/protein FDR; the row has neither reverse nor contaminant flag. The experiment-design file identifies the two EV and two supernatant conditions. These are deposited original results, not a claimed full-article Methods read or independent reanalysis of spectra. Group detection does not resolve all products, intravesicular topology or vesicle biogenesis. PMID:24769233(https://pubmed.ncbi.nlm.nih.gov/24769233/), original dataset.

Propagation, pathway and source boundaries

All 13 Reactome event summaries and complete target paths were inspected. ER-luminal assembly, extracellular secretion and substrate degradation are distinguished; modifying enzymes do their own chemistry. Broad ligand-event sets do not establish every isolated alpha2 contact. The NCAM summary names other collagen types while the graph reaches alpha2; no new direct NCAM interaction is manufactured. The GO-CAM index adds no proposed term.

Current donor records support transfer premises where non-propagated same-term evidence is present. Historical Ensembl/PTN placement remains distinct from those current records; a donor count or target self-presence is not used against PAINT.

Source and assay clarification

The alpha4-containing transfection experiment and the canonical alpha1/alpha2/alpha3 trimer describe different chain compositions. The current GO:0140158 definition covers the observed vWA-rich collagen trimer; GO:0005589 explicitly adds alpha3. The source index records both definitions, the direct parent edge and original Methods/Results/Figure 9 locators. Native alternative-chain uncertainties in the 2013 review do not reverse the engineered assay, and that assay is not presented as a natural human alpha4 complex. PMID:18400749(https://pubmed.ncbi.nlm.nih.gov/18400749/), PMID:23869615(https://pubmed.ncbi.nlm.nih.gov/23869615/).

The feeder-matrix source uses human placental stromal fibroblasts, not foreskin fibroblasts. Short quotations in the review anchor sample identity, canonical chain composition and the salivary paper's general fraction caveat. Exact peptide counts, normalized values and target groups remain tied to their original tables or workbooks; the quotations do not claim to reproduce unavailable table text. The unresolved target links in PMID:16893474, PMID:27068509 and PMID:28675934 remain distinct from the independent evidence supporting their retained biological annotations.