Details for: CSN3

Gene ID: 1448

Gene Type:  Protein-coding  - A gene that serves as a template for producing a messenger RNA (mRNA) molecule, which is then translated into a functional protein.

Symbol: CSN3

Ensembl ID: ENSG00000171209

Description: casein kappa

Selected Context(s):  Overall

Cell Significance Landscape

Contexts:

Associated with

Significant Cells

Cell Significance Index (CSI) scores for the chosen context(s)

  • acinar cell of salivary gland CL0002623
    CSI 0.34
    rCSI 7.92%
    PRS 99.96

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this specific cell.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.
Network Configuration

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  • Node Size: Proportional to Target Cell CSI magnitude
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Other Information

This section provides additional information about the gene, including a description generated by an AI language model and details about associated proteins.

## Summary [CSN3](/details-gene/1448), also known as kappa-casein, is a protein-coding gene located on chromosome 4q13.3. It encodes a major milk protein that is a critical component of casein micelles, which are responsible for stabilizing and transporting calcium phosphate in milk. Functionally, [CSN3](/details-gene/1448) is primarily associated with the biological process of **Lactation** ([GO:0007595](https://www.ebi.ac.uk/QuickGO/term/GO:0007595)) and protein stabilization. While classically studied in the context of mammary gland function, expression data suggests it may also have a significant role in other secretory tissues, with its highest expression significance noted in the [acinar cell of salivary gland](/details-cell/CL0002623). ## Cellular Roles and Expression Landscape The expression profile of [CSN3](/details-gene/1448) highlights a specialized role in secretory epithelial cells. **Overall**, the gene's most significant expression is observed in the [acinar cell of salivary gland](/details-cell/CL0002623) (CSI: 0.34). Acinar cells are the primary functional units of exocrine glands, responsible for producing and secreting the components of fluids like saliva. While the gene's canonical function is tied to milk production in mammary glands, this finding suggests a potentially broader role in the formation and composition of other exocrine secretions. The presence of [CSN3](/details-gene/1448) in salivary acinar cells may indicate its involvement in managing the protein and mineral content of saliva. The limited scope of the provided data precludes a detailed analysis of its expression in other cell lineages or its variability across different biological contexts. ## Pathways and Molecular Function The functional annotations for [CSN3](/details-gene/1448) align with its role as a secreted, structure-forming protein. It is a key participant in **Lactation** ([GO:0007595](https://www.ebi.ac.uk/QuickGO/term/GO:0007595)), a process extensively documented in the literature ([Link](https://doi.org/10.3109/10425179209034024), [Link](https://doi.org/10.1016/0378-1119(96)00351-4)). Its molecular functions include **Protein stabilization** ([GO:0050821](https://www.ebi.ac.uk/QuickGO/term/GO:0050821)) and **Protein binding** ([GO:0005515](https://www.ebi.ac.uk/QuickGO/term/GO:0005515)), which are fundamental to the assembly of stable casein micelles. As a secreted protein, it localizes to the **Extracellular region** ([GO:0005576](https://www.ebi.ac.uk/QuickGO/term/GO:0005576)) and **Extracellular space** ([GO:0005615](https://www.ebi.ac.uk/QuickGO/term/GO:0005615)). The involvement of [CSN3](/details-gene/1448) in broader **Transport of small molecules** ([R-HSA-382551](https://reactome.org/content/detail/R-HSA-382551)) pathways is consistent with the function of casein micelles in sequestering and delivering minerals like calcium. This transport function may be conserved in its role within the [acinar cell of salivary gland](/details-cell/CL0002623), potentially contributing to the mineral composition of saliva. ## Research Directions The observation of significant [CSN3](/details-gene/1448) expression in salivary glands, away from its classical context of lactation, opens up new avenues for research into the conserved mechanisms of exocrine secretion and oral biology. ### Proposed Hypotheses: 1. Expression of [CSN3](/details-gene/1448) in [acinar cell of salivary gland](/details-cell/CL0002623) contributes to the biochemical properties of saliva by stabilizing salivary proteins and sequestering calcium, thereby playing a protective role in maintaining oral health and preventing dental enamel demineralization. 2. [CSN3](/details-gene/1448) is part of a core exocrine gland secretory program, and its expression is not limited to mammary and salivary glands but may also be present in other exocrine tissues (e.g., pancreas, lacrimal glands), where it serves a general function in packaging and stabilizing secreted macromolecules. ### Key Experimental Approach: To test the first hypothesis regarding the role of [CSN3](/details-gene/1448) in saliva function, a targeted knockdown or knockout of the gene could be performed in a murine salivary gland organoid model. Secretions from control and [CSN3](/details-gene/1448)-deficient organoids would be collected and analyzed. Proteomic analysis via mass spectrometry would be used to assess changes in protein complex stability, while inductively coupled plasma mass spectrometry (ICP-MS) could quantify alterations in calcium and phosphate levels. A functional in vitro assay, where tooth enamel slices are incubated with the collected secretions, could directly measure the impact of [CSN3](/details-gene/1448) depletion on enamel remineralization and protection against acid challenge. ### Therapeutic Potential: Given that [CSN3](/details-gene/1448) encodes a secreted structural protein, it is not a conventional therapeutic target for inhibition or activation. However, its potential role in stabilizing saliva and maintaining mineral balance suggests a novel application. If its protective function in the oral cavity is validated, recombinant human kappa-casein or bioactive peptides derived from it could be developed as supplements for oral care products. Such products could be beneficial for treating conditions like xerostomia (dry mouth) or for enhancing the anti-caries properties of toothpaste and mouthwashes.

Genular Protein ID: 740852398

Symbol: CASK_HUMAN

Name: Kappa-casein

UniProtKB Accession Codes:

P07498 Q13575

Database IDs:

AGR 1 Allergome 1 AlphaFoldDB 1 Antibodypedia 1 Bgee 1 BioGRID 1 BioGRID-ORCS 1 BioMuta 1 CCDS 1 CTD 1 ChEMBL 1 ChiTaRS 1 DNASU 1 DisGeNET 1 DrugBank 1 EMBL 4 Ensembl 2 GO 4 GeneCards 1 GeneTree 1 GeneWiki 1 GenomeRNAi 1 GlyConnect 1 GlyCosmos 1 GlyGen 1 HGNC 1 HOGENOM 1 HPA 1 InParanoid 1 IntAct 1 InterPro 1 KEGG 1 MANE-Select 1 MIM 1 MINT 1 MassIVE 1 NCBI Taxonomy 1 OMA 1 OpenTargets 1 OrthoDB 1 PANTHER 2 PIR 1 PIRSF 1 PRO 1 PathwayCommons 1 PaxDb 1 PeptideAtlas 1 Pfam 1 PharmGKB 1 Pharos 1 PhosphoSitePlus 1 PhylomeDB 1 Proteomes 1 ProteomicsDB 1 RNAct 1 Reactome 1 RefSeq 3 STRING 1 SignaLink 1 SwissPalm 1 TopDownProteomics 1 TreeFam 1 UCSC 1 VEuPathDB 1 eggNOG 1 iPTMnet 1 neXtProt 1

Citations:

PubMed ID: 1296818

Title: Cloning and sequencing of human kappa-casein cDNA.

PubMed ID: 1296818

DOI: 10.3109/10425179209034024

PubMed ID: 8863730

Title: Structure of the human kappa-casein gene.

PubMed ID: 8863730

DOI: 10.1016/0378-1119(96)00351-4

PubMed ID: 15489334

Title: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

PubMed ID: 15489334

DOI: 10.1101/gr.2596504

PubMed ID: 4018271

Title: Preparation and amino acid sequence of human kappa-casein.

PubMed ID: 4018271

DOI: 10.1016/0014-5793(85)80872-3

PubMed ID: 7460900

Title: Localisation and importance of the sugar part of human casein.

PubMed ID: 7460900

DOI: 10.1111/j.1432-1033.1980.tb04946.x

PubMed ID: 10191473

Title: Structural features of a peptide corresponding to human kappa-casein residues 84-101 by 1H-nuclear magnetic resonance spectroscopy.

PubMed ID: 10191473

DOI: 10.1017/s0022029998003318

Sequence Information:

  • Length: 182
  • Mass: 20305
  • Checksum: 8A1609D2D5C94895
  • Sequence:
    • MKSFLLVVNA LALTLPFLAV EVQNQKQPAC HENDERPFYQ KTAPYVPMYY VPNSYPYYGT 
NLYQRRPAIA INNPYVPRTY YANPAVVRPH AQIPQRQYLP NSHPPTVVRR PNLHPSFIAI 
PPKKIQDKII IPTINTIATV EPTPAPATEP TVDSVVTPEA FSESIITSTP ETTTVAVTPP 
TA