Details for: CYBB

Gene ID: 1536

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: CYBB

Ensembl ID: ENSG00000165168

Description: cytochrome b-245 beta chain

Cell Significance Landscape

Associated with

Significant Cells

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

  • CD14-low, CD16-positive monocyte CL0002396
    CSI 82.56
    rCSI 63.61%
    PRS 96.03
  • elicited macrophage CL0000861
    CSI 44.47
    rCSI 40.83%
    PRS 96.84
  • naive B cell CL0000788
    CSI 34.7
    rCSI 29.76%
    PRS 96.01
  • memory B cell CL0000787
    CSI 34.18
    rCSI 33.75%
    PRS 96.25
  • intermediate monocyte CL0002393
    CSI 33.75
    rCSI 50.92%
    PRS 96.56
  • Hofbauer cell CL3000001
    CSI 29.97
    rCSI 56.57%
    PRS 96.74
  • classical monocyte CL0000860
    CSI 24.57
    rCSI 36.42%
    PRS 96.32
  • CD14-positive, CD16-positive monocyte CL0002397
    CSI 24.22
    rCSI 31.74%
    PRS 97.8
  • promonocyte CL0000559
    CSI 23.37
    rCSI 40.04%
    PRS 94.87
  • CD14-positive monocyte CL0001054
    CSI 22.85
    rCSI 28.46%
    PRS 97.5
  • B cell CL0000236
    CSI 21.97
    rCSI 29.39%
    PRS 92.56
  • class switched memory B cell CL0000972
    CSI 21.88
    rCSI 16.34%
    PRS 97.59
  • non-classical monocyte CL0000875
    CSI 21.88
    rCSI 35.07%
    PRS 96.75
  • plasmacytoid dendritic cell, human CL0001058
    CSI 20.95
    rCSI 14.63%
    PRS 95.92
  • alveolar macrophage CL0000583
    CSI 20.15
    rCSI 33.19%
    PRS 94.99
  • pro-B cell CL0000826
    CSI 16.61
    rCSI 13.75%
    PRS 94.32
  • kidney interstitial alternatively activated macrophage CL1000695
    CSI 16.45
    rCSI 42.87%
    PRS 94.95
  • lung interstitial macrophage CL4033043
    CSI 16.4
    rCSI 36.8%
    PRS 98.2
  • myeloid leukocyte CL0000766
    CSI 16.06
    rCSI 14.81%
    PRS 94.74
  • plasmacytoid dendritic cell CL0000784
    CSI 15.62
    rCSI 15.82%
    PRS 96.89
  • Kupffer cell CL0000091
    CSI 15.2
    rCSI 34.76%
    PRS 94.44
  • mononuclear phagocyte CL0000113
    CSI 14.76
    rCSI 32.49%
    PRS 95.62
  • microglial cell CL0000129
    CSI 14.59
    rCSI 58.73%
    PRS 92.6
  • monocyte CL0000576
    CSI 14.4
    rCSI 26.02%
    PRS 94.67
  • macrophage CL0000235
    CSI 14.3
    rCSI 26.01%
    PRS 93.63
  • conventional dendritic cell CL0000990
    CSI 13.88
    rCSI 11.58%
    PRS 87.93
  • alternatively activated macrophage CL0000890
    CSI 12.52
    rCSI 15.75%
    PRS 97.35
  • colon macrophage CL0009038
    CSI 12.03
    rCSI 55.56%
    PRS 97.87
  • CD14-positive, CD16-negative classical monocyte CL0002057
    CSI 11.65
    rCSI 70.45%
    PRS 97.36
  • immature B cell CL0000816
    CSI 11.4
    rCSI 8.47%
    PRS 97.41
  • early lymphoid progenitor CL0000936
    CSI 11.17
    rCSI 9.81%
    PRS 95.88
  • unswitched memory B cell CL0000970
    CSI 10.81
    rCSI 9.1%
    PRS 98.13
  • mature B cell CL0000785
    CSI 10.01
    rCSI 8.7%
    PRS 97.5
  • dendritic cell CL0000451
    CSI 9.99
    rCSI 12.31%
    PRS 92.74
  • lung macrophage CL1001603
    CSI 9.91
    rCSI 22.14%
    PRS 96.88
  • central nervous system macrophage CL0000878
    CSI 9.5
    rCSI 31.5%
    PRS 95.2
  • inflammatory macrophage CL0000863
    CSI 9.5
    rCSI 16.23%
    PRS 98.7
  • neutrophil CL0000775
    CSI 8.33
    rCSI 46.59%
    PRS 91.26
  • dendritic cell, human CL0001056
    CSI 8.13
    rCSI 12.49%
    PRS 97.3
  • myeloid cell CL0000763
    CSI 7.33
    rCSI 30.18%
    PRS 94.89
  • professional antigen presenting cell CL0000145
    CSI 7.02
    rCSI 24.17%
    PRS 95.53
  • plasmablast CL0000980
    CSI 6.91
    rCSI 5.44%
    PRS 94.92
  • Langerhans cell CL0000453
    CSI 6.51
    rCSI 9.94%
    PRS 97.65
  • CD1c-positive myeloid dendritic cell CL0002399
    CSI 6.1
    rCSI 7.37%
    PRS 96.86
  • myelocyte CL0002193
    CSI 5.26
    rCSI 34.54%
    PRS 97.22
  • promyelocyte CL0000836
    CSI 5.13
    rCSI 7.4%
    PRS 95.1
  • myeloid dendritic cell CL0000782
    CSI 3.99
    rCSI 5.79%
    PRS 98.44
  • megakaryocyte CL0000556
    CSI 3.94
    rCSI 17.11%
    PRS 93.82
  • granulocyte CL0000094
    CSI 3.79
    rCSI 5.79%
    PRS 96.38
  • transitional stage B cell CL0000818
    CSI 3.26
    rCSI 10.67%
    PRS 97.99
  • common lymphoid progenitor CL0000051
    CSI 2.93
    rCSI 3.92%
    PRS 98.41
  • germinal center B cell CL0000844
    CSI 2.83
    rCSI 8.44%
    PRS 95.49
  • fraction A pre-pro B cell CL0002045
    CSI 2.44
    rCSI 2.8%
    PRS 95.99
  • common dendritic progenitor CL0001029
    CSI 2.01
    rCSI 2.52%
    PRS 96.73
  • tissue-resident macrophage CL0000864
    CSI 1.5
    rCSI 7.04%
    PRS 97.92
  • metallothionein-positive alveolar macrophage CL4033042
    CSI 1.5
    rCSI 16.3%
    PRS 97.2
  • myeloid dendritic cell, human CL0001057
    CSI 1
    rCSI 5.61%
    PRS 98.25
  • CD8-positive, alpha-beta memory T cell, CD45RO-positive CL0001203
    CSI 0.89
    rCSI 1.07%
    PRS 76.12
  • B-2 B cell CL0000822
    CSI 0.86
    rCSI 18.33%
    PRS 97.71
  • pre-conventional dendritic cell CL0002010
    CSI 0.72
    rCSI 9.53%
    PRS 98.08
  • B-1 B cell CL0000819
    CSI 0.16
    rCSI 4.04%
    PRS 97.86

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.

Comma-separated if multiple.
Comma-separated if multiple.

Legend:
  • Query Gene
  • Node Color (Target Cell CSI, relative to current network):
    • Very High
    • 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 [CYBB](/details-gene/1536), or Cytochrome B-245 Beta Chain, is a protein-coding gene located on the X chromosome that encodes the large, membrane-bound catalytic subunit of the phagocyte NADPH oxidase complex, also known as gp91-phox. This complex is central to the innate immune response, responsible for generating superoxide and other reactive oxygen species (ROS) in a process termed the respiratory burst, which is critical for microbial killing. Consistent with this function, [CYBB](/details-gene/1536) shows the highest expression significance in professional phagocytes, including various monocyte subsets and macrophages. Mutations in this gene are the primary cause of X-linked Chronic Granulomatous Disease (CGD), a severe primary immunodeficiency characterized by recurrent, life-threatening bacterial and fungal infections ([OMIM: 306400](https://omim.org/entry/306400)) [Link](https://pubmed.ncbi.nlm.nih.gov/2425263/). ## Cellular Roles and Expression Landscape The expression profile of [CYBB](/details-gene/1536) underscores its fundamental role in the myeloid lineage of the innate immune system. **Overall**, the gene exhibits its highest significance as a defining marker in phagocytic cells. It is most prominently expressed in [CD14-low, CD16-positive monocytes](/details-cell/CL0002396) (CSI: 82.56), a subset known for potent inflammatory responses. High significance is also observed across the monocyte-macrophage spectrum, including [elicited macrophages](/details-cell/CL0000861), [intermediate monocytes](/details-cell/CL0002393), [classical monocytes](/details-cell/CL0000860), and specialized tissue-resident macrophages like [Hofbauer cells](/details-cell/CL3000001) and [alveolar macrophages](/details-cell/CL0000583). Interestingly, [CYBB](/details-gene/1536) also shows significant expression in cells of the adaptive immune system, specifically various B cell subsets such as [naive B cells](/details-cell/CL0000788) and [memory B cells](/details-cell/CL0000787). This suggests that NADPH oxidase-mediated ROS production may have functional roles beyond phagocytosis, potentially contributing to antigen presentation or cell signaling in lymphocytes. The gene's consistent high expression across these cell types highlights it as a crucial workhorse for host defense. ## Pathways and Molecular Function The molecular functions of [CYBB](/details-gene/1536) are tightly linked to its role as the core component of the NADPH oxidase enzyme. Its annotated functions include [superoxide-generating nad(p)h oxidase activity](/details-go/GO:0016175), [electron transfer activity](/details-go/GO:0009055), and binding cofactors such as [heme](/details-go/GO:0020037) and [flavin adenine dinucleotide](/details-go/GO:0050660). These activities are essential for the primary biological process of [superoxide anion generation](/details-go/GO:0042554) during the [respiratory burst](/details-go/GO:0045730). Pathway analysis confirms the central role of [CYBB](/details-gene/1536) in host defense. It is a key player in the [Innate immune system](/details-reactome/R-HSA-168249), particularly in [ROS and RNS production in phagocytes](/details-reactome/R-HSA-1222556) and [Neutrophil degranulation](/details-reactome/R-HSA-6798695). Its activity is tightly regulated by Rho GTPases, as indicated by its involvement in the [Rho GTPase cycle](/details-reactome/R-HSA-9012999) and pathways where [Rho GTPases activate NADPH oxidases](/details-reactome/R-HSA-5668599). This intricate regulation ensures that the potent ROS production is initiated only upon appropriate stimulation, such as pathogen encounter. The gene's involvement in both the [innate](/details-go/GO:0045087) and [adaptive immune systems](/details-reactome/R-HSA-1280218) highlights its broad importance in immunological processes. ## Research Directions The well-established role of [CYBB](/details-gene/1536) in phagocyte-mediated immunity provides a strong foundation for further research, particularly concerning its function in other immune cells and its therapeutic implications. **Proposed Hypotheses:** 1. Given the significant expression of [CYBB](/details-gene/1536) in [B cells](/details-cell/CL0000236), ROS produced by the NADPH oxidase complex may act as a second messenger to modulate B-cell receptor (BCR) signaling and regulate processes such as B-cell activation, survival, or differentiation. 2. The regulation of [CYBB](/details-gene/1536) expression and NADPH oxidase activity may be tailored to the specific microenvironment of different tissue-resident macrophages (e.g., [alveolar macrophages](/details-cell/CL0000583) vs. [Hofbauer cells](/details-cell/CL3000001)), contributing to their unique homeostatic and inflammatory functions beyond pathogen clearance. **Experimental Approach:** To test the first hypothesis regarding the role of [CYBB](/details-gene/1536) in B cells, a B-cell-specific conditional knockout mouse model (e.g., Cybb-floxed crossed with CD19-Cre mice) could be employed. Following immunization with a T-dependent antigen, key aspects of the humoral immune response could be evaluated. Specifically, analysis of germinal center formation by histology, B cell proliferation and activation by flow cytometry, and antigen-specific antibody titers and affinity by ELISA would reveal any defects. *In vitro*, BCR signaling could be directly assessed in isolated B cells by measuring calcium flux and phosphorylation of downstream signaling proteins following receptor cross-linking. **Therapeutic Potential:** As loss-of-function mutations in [CYBB](/details-gene/1536) cause the severe immunodeficiency X-linked CGD ([Link](https://pubmed.ncbi.nlm.nih.gov/3600769/)), therapeutic strategies are focused on **restoration of function**, not inhibition. [CYBB](/details-gene/1536) is a primary target for gene therapy, where a functional copy of the gene is delivered to hematopoietic stem cells to restore NADPH oxidase activity in their progeny. Therefore, [CYBB](/details-gene/1536) represents a critical target for curative treatments aimed at correcting a monogenic immune disorder, rather than a target for pharmacological modulation in other disease contexts.

Genular Protein ID: 3107619328

Symbol: CY24B_HUMAN

Name: Cytochrome b-245 heavy chain

UniProtKB Accession Codes:

Database IDs:

Citations:

PubMed ID: 12139950

Title: CYBB mutation analysis in X-linked chronic granulomatous disease.

PubMed ID: 12139950

DOI: 10.1006/clim.2002.5230

PubMed ID: 14702039

Title: Complete sequencing and characterization of 21,243 full-length human cDNAs.

PubMed ID: 14702039

DOI: 10.1038/ng1285

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: 2425263

Title: Cloning the gene for an inherited human disorder -- chronic granulomatous disease -- on the basis of its chromosomal location.

PubMed ID: 2425263

DOI: 10.1038/322032a0

PubMed ID: 3600768

Title: The glycoprotein encoded by the X-linked chronic granulomatous disease locus is a component of the neutrophil cytochrome b complex.

PubMed ID: 3600768

DOI: 10.1038/327717a0

PubMed ID: 9790760

Title: Nonhomologous recombination between the cytochrome b558 heavy chain gene (CYBB) and LINE-1 causes an X-linked chronic granulomatous disease.

PubMed ID: 9790760

DOI: 10.1006/geno.1998.5510

PubMed ID: 3600769

Title: The X-linked chronic granulomatous disease gene codes for the beta-chain of cytochrome b-245.

PubMed ID: 3600769

DOI: 10.1038/327720a0

PubMed ID: 10578014

Title: Evidence that the product of the human X-linked CGD gene, gp91-phox, is a voltage-gated H(+) pathway.

PubMed ID: 10578014

DOI: 10.1085/jgp.114.6.771

PubMed ID: 19028840

Title: Regulation of the phagocyte NADPH oxidase activity: phosphorylation of gp91phox/NOX2 by protein kinase C enhances its diaphorase activity and binding to Rac2, p67phox, and p47phox.

PubMed ID: 19028840

DOI: 10.1096/fj.08-114553

PubMed ID: 19159218

Title: Glycoproteomics analysis of human liver tissue by combination of multiple enzyme digestion and hydrazide chemistry.

PubMed ID: 19159218

DOI: 10.1021/pr8008012

PubMed ID: 24275569

Title: An enzyme assisted RP-RPLC approach for in-depth analysis of human liver phosphoproteome.

PubMed ID: 24275569

DOI: 10.1016/j.jprot.2013.11.014

PubMed ID: 28351984

Title: Eros is a novel transmembrane protein that controls the phagocyte respiratory burst and is essential for innate immunity.

PubMed ID: 28351984

DOI: 10.1084/jem.20161382

PubMed ID: 9224653

Title: Interaction of human neutrophil flavocytochrome b with cytosolic proteins: transferred-NOESY NMR studies of a gp91phox C-terminal peptide bound to p47phox.

PubMed ID: 9224653

DOI: 10.1042/bj3250249

PubMed ID: 2556453

Title: A missense mutation in the neutrophil cytochrome b heavy chain in cytochrome-positive X-linked chronic granulomatous disease.

PubMed ID: 2556453

DOI: 10.1172/jci114393

PubMed ID: 1710153

Title: Point mutations in the beta-subunit of cytochrome b558 leading to X-linked chronic granulomatous disease.

PubMed ID: 1710153

PubMed ID: 8101486

Title: A newly recognized point mutation in the cytochrome b558 heavy chain gene replacing alanine57 by glutamic acid, in a patient with cytochrome b positive X-linked chronic granulomatous disease.

PubMed ID: 8101486

DOI: 10.1007/bf01955051

PubMed ID: 7927345

Title: Two novel point mutations in the cytochrome b 558 heavy chain gene, detected in two Japanese patients with X-linked chronic granulomatous disease.

PubMed ID: 7927345

DOI: 10.1007/bf00201609

PubMed ID: 8182143

Title: A point mutation in gp91-phox of cytochrome b558 of the human NADPH oxidase leading to defective translocation of the cytosolic proteins p47-phox and p67-phox.

PubMed ID: 8182143

DOI: 10.1172/jci117207

PubMed ID: 8916969

Title: Identification of mutations in seven Chinese patients with X-linked chronic granulomatous disease.

PubMed ID: 8916969

PubMed ID: 9111587

Title: An in-frame triplet deletion within the gp91-phox gene in an adult X-linked chronic granulomatous disease patient with residual NADPH-oxidase activity.

PubMed ID: 9111587

DOI: 10.1111/j.1600-0609.1997.tb00928.x

PubMed ID: 9585602

Title: X-linked chronic granulomatous disease: mutations in the CYBB gene encoding the gp91-phox component of respiratory-burst oxidase.

PubMed ID: 9585602

DOI: 10.1086/301874

PubMed ID: 9856476

Title: A novel mutation at a probable heme-binding ligand in neutrophil cytochrome b558 in atypical X-linked chronic granulomatous disease.

PubMed ID: 9856476

DOI: 10.1007/s004390050836

PubMed ID: 9794433

Title: Nicotinamide-adenine dinucleotide phosphate oxidase assembly and activation in EBV-transformed B lymphoblastoid cell lines of normal and chronic granulomatous disease patients.

PubMed ID: 9794433

PubMed ID: 9667376

Title: Genetic analysis of 13 families with X-linked chronic granulomatous disease reveals a low proportion of sporadic patients and a high proportion of sporadic carriers.

PubMed ID: 9667376

DOI: 10.1203/00006450-199807000-00014

PubMed ID: 10089913

Title: Uncommon missense and splice mutations and resulting biochemical phenotypes in German patients with X-linked chronic granulomatous disease.

PubMed ID: 10089913

DOI: 10.1016/s0301-472x(98)00024-1

PubMed ID: 9888386

Title: Molecular analysis of chronic granulomatous disease caused by defects in gp91-phox.

PubMed ID: 9888386

DOI: 10.1002/(sici)1098-1004(1999)13:1<29::aid-humu3>3.0.co;2-x

PubMed ID: 10914676

Title: Statistical and mutational analysis of chronic granulomatous disease in Japan with special reference to gp91-phox and p22-phox deficiency.

PubMed ID: 10914676

DOI: 10.1007/s004390000288

PubMed ID: 11462241

Title: Characterization of 11 novel mutations in the X-linked chronic granulomatous disease (CYBB gene).

PubMed ID: 11462241

DOI: 10.1002/humu.1166

PubMed ID: 11997083

Title: Molecular and functional characterization of a new X-linked chronic granulomatous disease variant (X91+) case with a double missense mutation in the cytosolic gp91phox C-terminal tail.

PubMed ID: 11997083

DOI: 10.1016/s0925-4439(01)00110-7

PubMed ID: 15338276

Title: Functional analysis of two-amino acid substitutions in gp91 phox in a patient with X-linked flavocytochrome b558-positive chronic granulomatous disease by means of transgenic PLB-985 cells.

PubMed ID: 15338276

DOI: 10.1007/s00439-004-1173-z

PubMed ID: 18773283

Title: First report of clinical, functional, and molecular investigation of chronic granulomatous disease in nine Jordanian families.

PubMed ID: 18773283

DOI: 10.1007/s10875-008-9243-y

PubMed ID: 21278736

Title: Germline CYBB mutations that selectively affect macrophages in kindreds with X-linked predisposition to tuberculous mycobacterial disease.

PubMed ID: 21278736

DOI: 10.1038/ni.1992

PubMed ID: 22125116

Title: Identification and functional characterization of two novel mutations in the alpha-helical loop (residues 484-503) of CYBB/gp91(phox) resulting in the rare X91(+) variant of chronic granulomatous disease.

PubMed ID: 22125116

DOI: 10.1002/humu.22003

PubMed ID: 23910690

Title: Clinical, functional, and genetic characterization of chronic granulomatous disease in 89 Turkish patients.

PubMed ID: 23910690

DOI: 10.1016/j.jaci.2013.05.039

PubMed ID: 27666509

Title: A novel missense mutation in the NADPH binding domain of CYBB abolishes the NADPH oxidase activity in a male patient with increased susceptibility to infections.

PubMed ID: 27666509

DOI: 10.1016/j.micpath.2016.09.020

Sequence Information:

  • Length: 570
  • Mass: 65336
  • Checksum: 7E84051BD4000CE3
  • Sequence:
  • MGNWAVNEGL SIFVILVWLG LNVFLFVWYY RVYDIPPKFF YTRKLLGSAL ALARAPAACL 
    NFNCMLILLP VCRNLLSFLR GSSACCSTRV RRQLDRNLTF HKMVAWMIAL HSAIHTIAHL 
    FNVEWCVNAR VNNSDPYSVA LSELGDRQNE SYLNFARKRI KNPEGGLYLA VTLLAGITGV 
    VITLCLILII TSSTKTIRRS YFEVFWYTHH LFVIFFIGLA IHGAERIVRG QTAESLAVHN 
    ITVCEQKISE WGKIKECPIP QFAGNPPMTW KWIVGPMFLY LCERLVRFWR SQQKVVITKV 
    VTHPFKTIEL QMKKKGFKME VGQYIFVKCP KVSKLEWHPF TLTSAPEEDF FSIHIRIVGD 
    WTEGLFNACG CDKQEFQDAW KLPKIAVDGP FGTASEDVFS YEVVMLVGAG IGVTPFASIL 
    KSVWYKYCNN ATNLKLKKIY FYWLCRDTHA FEWFADLLQL LESQMQERNN AGFLSYNIYL 
    TGWDESQANH FAVHHDEEKD VITGLKQKTL YGRPNWDNEF KTIASQHPNT RIGVFLCGPE 
    ALAETLSKQS ISNSESGPRG VHFIFNKENF