Component

Human SLC44A4 isoform 1

710-residue hTPPT-1 tested in the 2014 study; transcript NM_025257.

2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What it acts on

  1. SLC44A4 isoform-1 fusion protein predominantly localized to the apical domain of polarized MDCK cells.

    Human SLC44A4 isoform 1 → Intestinal epithelium source_derived_draftungraded
    Experimental context and source evidence
    evidence-scope
    ARPE19; MDCK; human colon
    evidence_locator
    Figure 8
    evidence_spans
    [{"source_document": "artifacts/thiamine_transport_sources/PMC3924303.txt", "start_char": 47362, "end_char": 48692}]
    experimental_model
    Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging.
    limitations
    Canine model expressing human protein; not direct transepithelial flux.
    nutrient_topic
    Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
    organism
    Human constructs; human and canine host cells
    plain_language
    Its membrane targeting fits entry from the gut lumen.
    primary_references
    [nabokina-2014-slc44a4] Molecular identification and functional characterization of the human colonic thiamine pyrophosphate transporter (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC3924303/ DOI: 10.1074/jbc.M113.528257
    spatial_context
    Apical membrane of polarized epithelial model.
    tissue_or_cell_type
    ARPE19; MDCK; human colon

    Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 545–558

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging. · source_derived_draft · unverified_draft

    ### b1-slc44a4-apical-targeting SLC44A4 isoform-1 fusion protein predominantly localized to the apical domain of polarized MDCK cells. Condition category: normal nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Its membrane targeting fits entry from the gut lumen. organism: Human constructs; human and canine host cells tissue_or_cell_type: ARPE19; MDCK; human colon experimental_model: Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging. limitations: Canine model expressing human protein; not direct transepithelial flux. evidence_locator: Figure 8 spatial_context: Apical membrane of polarized epithelial model. evidence_spans: [{"source_document": "artifacts/thiamine_transport_sources/PMC3924303.txt", "start_char": 47362, "end_char": 48692}] evidence-scope: ARPE19; MDCK; human colon [nabokina-2014-slc44a4] Molecular identification and functional characterization of the human colonic thiamine pyrophosphate transporter (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC3924303/ DOI: 10.1074/jbc.M113.528257
    Complete structured claim and evidence

  2. Human SLC44A4 isoform 1 expression increased ThDP uptake in ARPE19 cells.

    Human SLC44A4 isoform 1 → Colonic thiamine diphosphate uptake source_derived_draftungraded
    Experimental context and source evidence
    evidence-scope
    ARPE19; MDCK; human colon
    evidence_locator
    Figure 1
    evidence_spans
    [{"source_document": "artifacts/thiamine_transport_sources/PMC3924303.txt", "start_char": 19781, "end_char": 21596}]
    experimental_model
    Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging.
    limitations
    Heterologous uptake; host dietary contribution unmeasured.
    nutrient_topic
    Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
    organism
    Human constructs; human and canine host cells
    plain_language
    This SLC44A4 form can carry phosphorylated B1.
    primary_references
    [nabokina-2014-slc44a4] Molecular identification and functional characterization of the human colonic thiamine pyrophosphate transporter (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC3924303/ DOI: 10.1074/jbc.M113.528257
    tissue_or_cell_type
    ARPE19; MDCK; human colon

    Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 517–529

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging. · source_derived_draft · unverified_draft

    ### b1-slc44a4-iso1-uptake Human SLC44A4 isoform 1 expression increased ThDP uptake in ARPE19 cells. Condition category: normal nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: This SLC44A4 form can carry phosphorylated B1. organism: Human constructs; human and canine host cells tissue_or_cell_type: ARPE19; MDCK; human colon experimental_model: Human SLC44A4 isoforms expressed in ARPE19 cells; polarized MDCK imaging. limitations: Heterologous uptake; host dietary contribution unmeasured. evidence_locator: Figure 1 evidence_spans: [{"source_document": "artifacts/thiamine_transport_sources/PMC3924303.txt", "start_char": 19781, "end_char": 21596}] evidence-scope: ARPE19; MDCK; human colon [nabokina-2014-slc44a4] Molecular identification and functional characterization of the human colonic thiamine pyrophosphate transporter (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC3924303/ DOI: 10.1074/jbc.M113.528257
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

    Evidence, AI assistance and curation standards