Details for: CGB2

Gene ID: 114336

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: CGB2

Ensembl ID: ENSG00000104818

Description: chorionic gonadotropin subunit beta 2

Cell Significance Landscape

Associated with

Significant Cells

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

  • syncytiotrophoblast cell CL0000525
    CSI 11.54
    rCSI 33.23%
    PRS 100

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 Color (Target Cell CSI, relative to current network):
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    • CSI N/A
  • Node Size: Proportional to Target Cell CSI magnitude
  • STRING PPI Edge
  • Shared Pathway Edge (ONTOLOGY)

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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 [CGB2](/details-gene/114336), or Chorionic Gonadotropin Subunit Beta 2, is a protein-coding gene located on chromosome 19q13.33. It encodes a beta subunit of human chorionic gonadotropin (hCG), a critical placental hormone essential for establishing and maintaining pregnancy. The gene's function as a hormone ([GO:0005179](https://www.ebi.ac.uk/QuickGO/term/GO:0005179)) is executed through G protein-coupled receptor signaling ([GO:0007186](https://www.ebi.ac.uk/QuickGO/term/GO:0007186)). Expression analysis reveals that [CGB2](/details-gene/114336) is a highly specific marker for the [syncytiotrophoblast cell](/details-cell/CL0000525), the primary site of hCG synthesis in the placenta. Its highly restricted expression pattern underscores its specialized role in reproductive biology. ## Cellular Roles and Expression Landscape The expression profile of [CGB2](/details-gene/114336) is characterized by exceptional cellular specificity. **Overall**, the gene's significance is almost exclusively confined to the [syncytiotrophoblast cell](/details-cell/CL0000525) of the placenta, where it holds a very high Cell Significance Index (CSI: 11.54). [Syncytiotrophoblast cells](/details-cell/CL0000525) are specialized epithelial cells that form the outer layer of the placental villi and are responsible for hormone production and nutrient exchange between the mother and fetus. The high CSI value suggests that [CGB2](/details-gene/114336) is not only abundant in these cells but also a defining marker of their identity and primary function. This is consistent with studies quantifying HCG beta gene transcription, which confirm that trophoblastic tissues are the principal site of its expression [Link](https://doi.org/10.1093/molehr/gam082). The gene's lack of significant expression in other cell types highlights its dedicated role in placental endocrinology. ## Pathways and Molecular Function Functionally, [CGB2](/details-gene/114336) is annotated with **hormone activity** ([GO:0005179](https://www.ebi.ac.uk/QuickGO/term/GO:0005179)). The protein product is a subunit of the heterodimeric glycoprotein hCG, which acts by stimulating the corpus luteum to produce progesterone, thereby maintaining the uterine lining and preventing menstruation during early pregnancy. This hormonal signal is transduced via the **G protein-coupled receptor signaling pathway** ([GO:0007186](https://www.ebi.ac.uk/QuickGO/term/GO:0007186)), specifically by binding to the luteinizing hormone/choriogonadotropin receptor (LHCGR). As a secreted hormone, its presence in the **extracellular space** ([GO:0005615](https://www.ebi.ac.uk/QuickGO/term/GO:0005615)) is critical for its endocrine function, while its initial synthesis occurs within the **cytoplasm** ([GO:0005737](https://www.ebi.ac.uk/QuickGO/term/GO:0005737)) of [syncytiotrophoblast cells](/details-cell/CL0000525). ## Research Directions Research has indicated that the expression of hCG beta-subunit genes is altered in pregnancies that fail compared to normal pregnancies, suggesting that aberrant regulation of genes like [CGB2](/details-gene/114336) could be implicated in pregnancy complications [Link](https://doi.org/10.1093/humrep/dei261). This provides a clear avenue for further investigation into the molecular mechanisms governing placental health. Based on its function and expression, several testable hypotheses can be proposed: 1. **Hypothesis:** Subtle variations in the transcriptional regulation of [CGB2](/details-gene/114336) within [syncytiotrophoblast cells](/details-cell/CL0000525) during the first trimester are a key determinant of pregnancy outcome. Lower-than-optimal expression may lead to insufficient luteal support and contribute to early pregnancy loss. 2. **Hypothesis:** The evolutionary recent origin of chorionic gonadotropin within primates [Link](https://doi.org/10.1093/oxfordjournals.molbev.a004085) suggests that its regulatory network is also novel. It is hypothesized that primate-specific transcription factors or enhancer elements are responsible for the highly specific expression of [CGB2](/details-gene/114336) in the syncytiotrophoblast, and disruption of these factors could underlie certain forms of infertility. **Experimental Approach:** To test the first hypothesis, one could employ placental trophoblast organoids derived from first-trimester tissue. Using CRISPR interference (CRISPRi) to specifically knockdown [CGB2](/details-gene/114336) expression, researchers could measure the resulting changes in the organoid secretome via mass spectrometry and assess the functional impact on co-cultured endometrial stromal cells by quantifying decidualization markers (e.g., prolactin, IGFBP1) via RT-qPCR. This would directly link [CGB2](/details-gene/114336) expression levels to the physiological processes it regulates. **Therapeutic Potential:** As the protein product of [CGB2](/details-gene/114336) is a component of hCG, its therapeutic potential lies primarily in diagnostics and monitoring rather than direct molecular targeting. The measurement of hCG is already a foundational clinical tool for pregnancy detection and assessment of gestational health. Further research into gene-specific expression, distinguishing [CGB2](/details-gene/114336) from other CGB paralogs, could lead to the development of more sensitive and specific biomarkers for predicting adverse pregnancy outcomes, such as miscarriage or pre-eclampsia, at a much earlier stage.

Genular Protein ID: 2844809072

Symbol: CGB2_HUMAN

Name: Choriogonadotropin subunit beta variant 2

UniProtKB Accession Codes:

Q6NT52 B9ZVM5 H9KV56

Database IDs:

AGR 1 AlphaFoldDB 1 Antibodypedia 1 Bgee 1 BioGRID-ORCS 1 BioMuta 1 CCDS 1 CDD 1 CTD 1 DMDM 1 DNASU 1 DisGeNET 1 EMBL 2 Ensembl 1 ExpressionAtlas 1 GO 4 Gene3D 1 GeneCards 1 GeneTree 1 GenomeRNAi 1 GlyCosmos 1 GlyGen 1 HGNC 1 HPA 1 InParanoid 1 IntAct 1 InterPro 4 KEGG 1 MANE-Select 1 MIM 1 MINT 1 MassIVE 1 NCBI Taxonomy 1 OMA 1 OpenTargets 1 OrthoDB 1 PANTHER 2 PRO 1 PROSITE 2 PathwayCommons 1 PaxDb 1 PeptideAtlas 1 Pfam 1 Pharos 1 PhosphoSitePlus 1 PhylomeDB 1 Proteomes 1 ProteomicsDB 1 RNAct 1 RefSeq 1 SMART 1 SMR 1 STRING 1 SUPFAM 1 SignaLink 1 TreeFam 1 VEuPathDB 1 eggNOG 1 iPTMnet 1 neXtProt 1

Citations:

PubMed ID: 18048458

Title: Fine-scale quantification of HCG beta gene transcription in human trophoblastic and non-malignant non-trophoblastic tissues.

PubMed ID: 18048458

DOI: 10.1093/molehr/gam082

PubMed ID: 15057824

Title: The DNA sequence and biology of human chromosome 19.

PubMed ID: 15057824

DOI: 10.1038/nature02399

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: 11861891

Title: Chorionic gonadotropin has a recent origin within primates and an evolutionary history of selection.

PubMed ID: 11861891

DOI: 10.1093/oxfordjournals.molbev.a004085

PubMed ID: 16123088

Title: Expression of beta-subunit of HCG genes during normal and failed pregnancy.

PubMed ID: 16123088

DOI: 10.1093/humrep/dei261

Sequence Information:

  • Length: 163
  • Mass: 17374
  • Checksum: 823CEF334B9183F6
  • Sequence:
    • MSKGLLLLLL LSMGGTWASK EPLRPRCRPI NATLAVEKEG CPVCITVNTT ICAGYCPTMT 
RVLQGVLPAL PQVVCNYRDV RFESIRLPGC PRGVNPVVSY AVALSCQCAL CRRSTTDCGG 
PKDHPLTCDD PRFQASSSSK APPPSLPSPS RLPGPSDTPI LPQ