Details for: CABP5

Gene ID: 56344

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: CABP5

Ensembl ID: ENSG00000105507

Description: calcium binding protein 5

Cell Significance Landscape

Associated with

Significant Cells

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

  • OFF-bipolar cell CL0000750
    CSI 23.71
    rCSI 32.42%
    PRS 99.54
  • ON-bipolar cell CL0000749
    CSI 18.74
    rCSI 27.85%
    PRS 99.51
  • retinal cone cell CL0000573
    CSI 13.3
    rCSI 21.4%
    PRS 98.82
  • rod bipolar cell CL0000751
    CSI 12.32
    rCSI 22.15%
    PRS 99.47
  • retinal bipolar neuron CL0000748
    CSI 11.43
    rCSI 21.41%
    PRS 99.14
  • retinal rod cell CL0000604
    CSI 11.33
    rCSI 19.97%
    PRS 99.07
  • platelet CL0000233
    CSI 9.48
    rCSI 39.32%
    PRS 98.69
  • diffuse bipolar 3a cell CL4033029
    CSI 5.46
    rCSI 37.14%
    PRS 98.97
  • flat midget bipolar cell CL4033033
    CSI 5.32
    rCSI 38.02%
    PRS 98.79
  • megakaryocyte CL0000556
    CSI 4.83
    rCSI 20.95%
    PRS 99.08
  • eye photoreceptor cell CL0000287
    CSI 3.39
    rCSI 38.1%
    PRS 99.67
  • OFFx cell CL4033036
    CSI 2.94
    rCSI 13.82%
    PRS 98.93
  • diffuse bipolar 3b cell CL4033030
    CSI 1.34
    rCSI 8.87%
    PRS 98.91
  • cone retinal bipolar cell CL0000752
    CSI 1.08
    rCSI 14.04%
    PRS 99.27

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

Explore relationships of the current gene. Select an Interaction Source: 'ONTOLOGY' for shared pathways (GO/Reactome) or 'STRING' for protein-protein interactions. Further refine by selecting context genes and comparing Cell Significance Index (CSI) scores between baseline and target cell types and their specific contexts.

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Legend:
  • Query Gene
  • Node Color (Target Cell CSI, relative to current network):
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    • High
    • Medium
    • Low
    • Very Low
    • 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 [CABP5](/details-gene/56344) (Calcium Binding Protein 5) is a protein-coding gene located on chromosome 19q13.33. It encodes a member of a novel subfamily of calcium-binding proteins that share structural similarities with calmodulin ([Link](https://doi.org/10.1074/jbc.275.2.1247)). Functionally, [CABP5](/details-gene/56344) is involved in calcium-dependent [signal transduction](/details-cell/GO:0007165) and acts as a [calcium channel regulator](/details-cell/GO:0005246). Expression data indicates a highly specialized role for this gene, with its significance overwhelmingly concentrated in neuronal cell types of the retina. Specifically, it is a top marker for [OFF-bipolar cell](/details-cell/CL0000750), [ON-bipolar cell](/details-cell/CL0000749), and photoreceptor cells such as the [retinal cone cell](/details-cell/CL0000573), suggesting a critical function in the processing of visual information. ## Cellular Roles and Expression Landscape The expression profile of [CABP5](/details-gene/56344) reveals its profound importance within the neurosensory network of the eye. **Overall**, the gene shows exceptional significance in various subtypes of retinal neurons responsible for transmitting signals from photoreceptors to ganglion cells. It is the most significant marker for [OFF-bipolar cell](/details-cell/CL0000750) (CSI: 23.71) and is also highly significant in [ON-bipolar cell](/details-cell/CL0000749) (CSI: 18.74) and [rod bipolar cell](/details-cell/CL0000751) (CSI: 12.32). Furthermore, [CABP5](/details-gene/56344) is highly expressed in the primary light-sensing cells themselves, including the [retinal cone cell](/details-cell/CL0000573) and [retinal rod cell](/details-cell/CL0000604). This co-localization in both photoreceptors and their immediate downstream targets, the bipolar cells, suggests a pivotal role for [CABP5](/details-gene/56344) in modulating the synaptic transmission that underpins vision. The highly specific expression within the retina is consistent with research identifying distinct roles for various calcium-binding proteins in visual processing ([Link](https://doi.org/10.1016/s0167-4889(00)00099-9)). Outside of the retina, the gene also shows moderate significance in [platelet](/details-cell/CL0000233)s (CSI: 9.48) and their precursors, [megakaryocyte](/details-cell/CL0000556)s (CSI: 4.83). This secondary expression pattern may indicate a role for [CABP5](/details-gene/56344) in calcium-mediated processes related to hemostasis or thrombopoiesis, though this function appears less prominent than its role in the visual system. ## Pathways and Molecular Function The functional annotations for [CABP5](/details-gene/56344) are highly consistent with its observed expression pattern in electrically excitable cells of the retina. The protein's primary molecular functions are [calcium ion binding](/details-cell/GO:0005509) and [calcium channel regulator activity](/details-cell/GO:0005246). These activities are integral to the biological process of [signal transduction](/details-cell/GO:0007165). Within the cell, [CABP5](/details-gene/56344) is localized to the [cytoplasm](/details-cell/GO:0005737) and [cytosol](/details-cell/GO:0005829), positioning it to interact with intracellular signaling cascades and membrane-bound ion channels. In the context of retinal neurons, the ability of [CABP5](/details-gene/56344) to bind calcium and regulate ion channels is critical for modulating neurotransmitter release and shaping postsynaptic potentials. Calcium influx is the primary trigger for synaptic vesicle fusion at the photoreceptor-bipolar cell synapse. The high expression of [CABP5](/details-gene/56344) in these cells suggests it acts as a calcium sensor or buffer that fine-tunes the synaptic response to light, thereby controlling the sensitivity and kinetics of the visual signal as it is passed through the retinal layers. ## Research Directions The highly specific expression and function of [CABP5](/details-gene/56344) in the retina point to its potential involvement in both normal visual processing and retinal diseases. Further research is warranted to elucidate its precise mechanisms and clinical relevance. **Testable Hypotheses:** 1. Given its role as a [calcium channel regulator](/details-cell/GO:0005246) and its high expression in photoreceptors and bipolar cells, [CABP5](/details-gene/56344) is hypothesized to be a key modulator of the L-type CaV1.4 calcium channels at the photoreceptor synaptic terminal, thereby controlling the gain and temporal dynamics of glutamate release onto bipolar cells. 2. The expression of [CABP5](/details-gene/56344) in [platelet](/details-cell/CL0000233)s suggests it may regulate calcium-dependent platelet activation. It is hypothesized that [CABP5](/details-gene/56344) modulates store-operated calcium entry (SOCE) or other calcium influx pathways required for platelet aggregation and granule secretion. **Proposed Experiment:** To test the primary hypothesis regarding the role of [CABP5](/details-gene/56344) in visual signal transmission, a knockout mouse model (Cabp5-/-) could be utilized. Electroretinography (ERG) would be performed on these mice and wild-type controls to assess retinal function. Specifically, the b-wave of the ERG, which reflects the activity of bipolar cells, would be of particular interest. A change in the amplitude or kinetics of the b-wave in knockout animals would provide strong evidence for the involvement of [CABP5](/details-gene/56344) in the photoreceptor-to-bipolar cell synapse. This could be followed by patch-clamp electrophysiology on retinal slices to directly measure synaptic currents and membrane properties of bipolar cells in the absence of the protein. **Therapeutic Potential:** Due to its highly restricted expression pattern, primarily within the retina, [CABP5](/details-gene/56344) is an unlikely target for systemic drug development. However, its specificity makes it a compelling candidate for involvement in inherited retinal disorders, analogous to other retinal calcium-binding proteins ([Link](https://doi.org/10.1016/s0167-4889(00)00099-9)). Should loss-of-function mutations in [CABP5](/details-gene/56344) be linked to conditions like congenital stationary night blindness or cone-rod dystrophies, it would become a prime target for AAV-mediated gene replacement therapy. Such a strategy would aim to restore protein function specifically in affected retinal cells, minimizing off-target effects.

Genular Protein ID: 184644866

Symbol: CABP5_HUMAN

Name: Calcium-binding protein 5

UniProtKB Accession Codes:

Q9NP86 A0AUY4

Database IDs:

AGR 1 AlphaFoldDB 1 Antibodypedia 1 Bgee 1 BioGRID 1 BioGRID-ORCS 1 BioMuta 1 CCDS 1 CDD 1 CTD 1 ChEBI 14 DMDM 1 DNASU 1 DisGeNET 1 EMBL 7 Ensembl 1 GO 5 Gene3D 1 GeneCards 1 GeneTree 1 GenomeRNAi 1 HGNC 1 HOGENOM 1 HPA 1 InParanoid 1 IntAct 1 InterPro 4 KEGG 1 MANE-Select 1 MIM 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 PharmGKB 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 UCSC 1 VEuPathDB 1 eggNOG 1 neXtProt 1

Citations:

PubMed ID: 10625670

Title: Five members of a novel Ca(2+)-binding protein (CABP) subfamily with similarity to calmodulin.

PubMed ID: 10625670

DOI: 10.1074/jbc.275.2.1247

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: 11108966

Title: Ca(2+)-binding proteins in the retina: from discovery to etiology of human disease.

PubMed ID: 11108966

DOI: 10.1016/s0167-4889(00)00099-9

PubMed ID: 19338761

Title: Membrane targeting of the EF-hand containing calcium-sensing proteins CaBP7 and CaBP8.

PubMed ID: 19338761

DOI: 10.1016/j.bbrc.2009.01.177

Sequence Information:

  • Length: 173
  • Mass: 19826
  • Checksum: BB4DD28E9ECC55AF
  • Sequence:
    • MQFPMGPACI FLRKGIAEKQ RERPLGQDEI EELREAFLEF DKDRDGFISC KDLGNLMRTM 
GYMPTEMELI ELGQQIRMNL GGRVDFDDFV ELMTPKLLAE TAGMIGVQEM RDAFKEFDTN 
GDGEITLVEL QQAMQRLLGE RLTPREISEV VREADVNGDG TVDFEEFVKM MSR