Renal epithelial sodium/bicarbonate transport: molecular mechanisms & dependencies

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.

Human evidence only

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 acts on it

Mutagenesis of NBCe1 residues E91 or R298 reduced transport function in the expression assay.
NBCe1-A splice variant → Renal epithelial sodium/bicarbonate transport source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/sodium-research/18441326.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c", "start_char": 0, "end_char": 1213, "text_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c"}
experimental_model
Homology modeling and site-directed mutagenesis with oocyte transport assays
exposure
E91 and R298 mutations and charge-reversal construct
limitations
Structure model plus functional assay; charge rescue does not establish clinical treatment or dietary sodium responsiveness.
nutrient_topic
Sodium research collection; topical membership is not evidence of a direct dietary effect. · Sodium
organism
Human kidney NBCe1 in Xenopus oocytes
plain_language
Acid–base regulation depends on the protein’s structure as well as available sodium.
primary_references
[sodium-p18441326] Entry to "formula tunnel" revealed by SLC4A4 human mutation and structural model. (2008). https://pubmed.ncbi.nlm.nih.gov/18441326/ DOI: 10.1074/jbc.m709819200
tissue_or_cell_type
Sodium/bicarbonate transporter N-terminal domain
trigger_kind
machinery_impairment Imported condition classification; unverified.
Sodium: gradients, nutrient transport, fluid regulation and loss states (2026-09-17) · lines 707–718
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Homology modeling and site-directed mutagenesis with oocyte transport assays · source_derived_draft · unverified_draft
### sodium-nbce1-mutation Mutagenesis of NBCe1 residues E91 or R298 reduced transport function in the expression assay. Condition category: machinery_impairment nutrient_topic: Sodium research collection; topical membership is not evidence of a direct dietary effect. plain_language: Acid–base regulation depends on the protein’s structure as well as available sodium. organism: Human kidney NBCe1 in Xenopus oocytes tissue_or_cell_type: Sodium/bicarbonate transporter N-terminal domain experimental_model: Homology modeling and site-directed mutagenesis with oocyte transport assays limitations: Structure model plus functional assay; charge rescue does not establish clinical treatment or dietary sodium responsiveness. exposure: E91 and R298 mutations and charge-reversal construct evidence_span: {"source_cache": "artifacts/sodium-research/18441326.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c", "start_char": 0, "end_char": 1213, "text_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c"} [sodium-p18441326] Entry to "formula tunnel" revealed by SLC4A4 human mutation and structural model. (2008). https://pubmed.ncbi.nlm.nih.gov/18441326/ DOI: 10.1074/jbc.m709819200
Complete structured claim and evidence
The E91R/R298E charge-reversal construct restored transport function in the study.
Human kidney NBCe1 E91R/R298E charge-reversal construct → Renal epithelial sodium/bicarbonate transport source_derived_draftungraded
Experimental context and source evidence
availability_state
machinery_impairment Imported condition classification; unverified.
evidence_span
{"source_cache": "artifacts/sodium-research/18441326.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c", "start_char": 0, "end_char": 1213, "text_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c"}
experimental_model
Homology modeling and site-directed mutagenesis with oocyte transport assays
exposure
E91 and R298 mutations and charge-reversal construct
limitations
Structure model plus functional assay; charge rescue does not establish clinical treatment or dietary sodium responsiveness.
nutrient_topic
Sodium research collection; topical membership is not evidence of a direct dietary effect. · Sodium
organism
Human kidney NBCe1 in Xenopus oocytes
plain_language
An engineered protein repair supported a specific interaction between these residues.
primary_references
[sodium-p18441326] Entry to "formula tunnel" revealed by SLC4A4 human mutation and structural model. (2008). https://pubmed.ncbi.nlm.nih.gov/18441326/ DOI: 10.1074/jbc.m709819200
tissue_or_cell_type
Sodium/bicarbonate transporter N-terminal domain
trigger_kind
machinery_impairment Imported condition classification; unverified.
Sodium: gradients, nutrient transport, fluid regulation and loss states (2026-09-17) · lines 720–731
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Homology modeling and site-directed mutagenesis with oocyte transport assays · source_derived_draft · unverified_draft
### sodium-nbce1-rescue The E91R/R298E charge-reversal construct restored transport function in the study. Condition category: machinery_impairment nutrient_topic: Sodium research collection; topical membership is not evidence of a direct dietary effect. plain_language: An engineered protein repair supported a specific interaction between these residues. organism: Human kidney NBCe1 in Xenopus oocytes tissue_or_cell_type: Sodium/bicarbonate transporter N-terminal domain experimental_model: Homology modeling and site-directed mutagenesis with oocyte transport assays limitations: Structure model plus functional assay; charge rescue does not establish clinical treatment or dietary sodium responsiveness. exposure: E91 and R298 mutations and charge-reversal construct evidence_span: {"source_cache": "artifacts/sodium-research/18441326.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c", "start_char": 0, "end_char": 1213, "text_sha256": "3ca538a7ecb046a47f9246778b3dede99c503a45c6048f75541612c8db37448c"} [sodium-p18441326] Entry to "formula tunnel" revealed by SLC4A4 human mutation and structural model. (2008). https://pubmed.ncbi.nlm.nih.gov/18441326/ DOI: 10.1074/jbc.m709819200
Complete structured claim and evidence

The events it takes part in

A mechanism often involves more than two components. These are the full events, with every participant and its role.

Situations it appears in

Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.

In the sources

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

Open hypotheses

Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.

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

Renal epithelial sodium/bicarbonate transport