ZAP70

Last updated
ZAP70
Protein ZAP70 PDB 1m61.png
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases ZAP70 , SRK, STCD, STD, TZK, ZAP-70, zeta chain of T cell receptor associated protein kinase 70kDa, zeta chain of T cell receptor associated protein kinase 70, zeta chain of T-cell receptor associated protein kinase 70, IMD48, ADMIO2
External IDs OMIM: 176947 MGI: 99613 HomoloGene: 839 GeneCards: ZAP70
Orthologs
SpeciesHumanMouse
Entrez

7535

22637

Ensembl

ENSG00000115085

ENSMUSG00000026117

UniProt

P43403

P43404

RefSeq (mRNA)

NM_001079
NM_207519
NM_001378594

NM_009539
NM_001289612
NM_001289765
NM_001289766

RefSeq (protein)

NP_001070
NP_997402
NP_001365523

NP_001276541
NP_001276694
NP_001276695
NP_033565

Location (UCSC) Chr 2: 97.71 – 97.74 Mb Chr 1: 36.8 – 36.82 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

ZAP-70 (Zeta-chain-associated protein kinase 70) is a protein normally expressed near the surface membrane of lymphocytes (T cells, natural killer cells, and a subset of B cells). [5] It is most prominently known to be recruited upon antigen binding to the T cell receptor (TCR), and it plays a critical role in T cell signaling.

ZAP-70 was initially discovered in TCR-stimulated Jurkat cells, an immortal line of human T lymphocytes, in 1991. [6] Its molecular weight is 70 kDa, and it is a member of the protein-tyrosine kinase family and is a close homolog of SYK. SYK and ZAP70 share a common evolutionary origin and split from a common ancestor in the jawed vertebrates. [7] The importance of ZAP-70 in T cell activation was determined when comparing ZAP-70 expression in patients with SCID (severe combined immunodeficiency). [6] ZAP-70 deficient individuals were found to have no functioning T cells in their peripheral blood, suggesting that ZAP-70 is a critical component of T cell activation and development. [6]

ZAP-70 expression in B cells is correlated with the development of chronic lymphocytic leukemia (CLL).

Function

The T cell receptor has no innate enzymatic activity. Due to this, T cell receptors rely on signaling molecules to transduce a signal from the cell membrane. ZAP-70 is a critical cytoplasmic tyrosine kinase that initiates a signal pathway downstream of an activated T cell receptor. [8]

T lymphocytes are activated by engagement of the T cell receptor with processed antigen fragments presented by professional antigen presenting cells (i.e. macrophages, dendritic cells, Langerhans cells and B cells) via the MHC. Upon this activation, the TCR co-receptor CD4 (expressed on T helper cells) or CD8 (expressed on cytotoxic T cells) binds to the MHC, activating the co-receptor associated tyrosine kinase Lck. Lck is moved near the CD3 complex and phosphorylates the tyrosines in the immunoreceptor tyrosine-based activation motifs (ITAMS), creating a docking site for ZAP-70. [9] The most important member of the CD3 family is CD3-zeta, to which ZAP-70 binds (hence the abbreviation). The tandem SH2-domains of ZAP-70 are engaged by the doubly phosphorylated ITAMs of CD3-zeta, which positions ZAP-70 to phosphorylate the transmembrane protein linker for activation of T cells (LAT). [9] Phosphorylated LAT, in turn, serves as a docking site to which a number of signaling proteins bind, including the SH2-domain-containing leukocyte protein of 76 kDa (SLP-76). [9] SLP-76 is also phosphorylated by ZAP-70, which requires its activation by Src family kinases. [10] The final outcome of T cell activation is the transcription of several gene products which allow the T cells to differentiate, proliferate, and secrete a number of cytokines.

Clinical Significance

Due to its role in lymphocyte signaling, ZAP-70 has been associated with several diseases affecting lymphocytes. ZAP-70 expression is a significant indicator of the survival of lymphocytes and has been notably associated with chronic lymphocytic leukemia (CLL). [11] CLL is a cancer that develops from overproduction of B cells in the bone marrow.

In people with CLL, higher levels of ZAP-70 confers a worse prognosis; CLL patients that are positive for the marker ZAP-70 have an average survival of 8 years, whereas those that are negative for ZAP-70 have an average survival of more than 25 years. Many patients, especially older ones, with slowly progressing disease can be reassured and may not need any treatment in their lifetimes. [12] In individuals with CLL, higher levels of ZAP-70 is associated with a higher number of malignant B cells activated. [5] Increased expression of ZAP-70 in B cell malignancies is correlated with increased association between malignant B cells and the immune environment, suggesting a complex role for ZAP-70 in B cell signaling. [5]

In systemic lupus erythematosus, the Zap-70 receptor pathway is missing and the homolog Syk takes its place. [13]

ZAP-70 deficiency results in a form of autosomal recessive immune deficiency named combined immunodeficiency. [14] Patients afflicted with combined immunodeficiency have a normal lymphocyte count, but they have low concentrations of T helper cells and cytotoxic T cells. [14] Patients were also found to have irregular lymphocyte proliferation responses. [14] These effects suggest that a deficiency in ZAP-70 results in decreased rates of T cell activation and subsequent signal transductions. [14]

Interactions

ZAP-70 has been shown to interact with:

See also

Related Research Articles

<span class="mw-page-title-main">CD4</span> Marker on immune cells

In molecular biology, CD4 is a glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). CD4 is found on the surface of immune cells such as T helper cells, monocytes, macrophages, and dendritic cells. It was discovered in the late 1970s and was originally known as leu-3 and T4 before being named CD4 in 1984. In humans, the CD4 protein is encoded by the CD4 gene.

<span class="mw-page-title-main">T-cell receptor</span> Protein complex on the surface of T cells that recognises antigens

The T-cell receptor (TCR) is a protein complex found on the surface of T cells, or T lymphocytes, that is responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules. The binding between TCR and antigen peptides is of relatively low affinity and is degenerate: that is, many TCRs recognize the same antigen peptide and many antigen peptides are recognized by the same TCR.

<span class="mw-page-title-main">Lck</span> Lymphocyte protein

Lck is a 56 kDa protein that is found inside specialized cells of the immune system called lymphocytes. The Lck is a member of Src kinase family (SFK), it is important for the activation of the T-cell receptor signaling in both naive T cells and effector T cells. The role of the Lck is less prominent in the activation or in the maintenance of memory CD8 T cells in comparison to CD4 T cells. In addition, the role of the lck varies among the memory T cells subsets. It seems that in mice, in the effector memory T cells (TEM) population, more than 50% of lck is present in a constitutively active conformation, whereas, only less than 20% of lck is present as active form of lck. These differences are due to differential regulation by SH2 domain–containing phosphatase-1 (Shp-1) and C-terminal Src kinase.

<span class="mw-page-title-main">P110δ</span> Protein-coding gene in the species Homo sapiens

Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta isoform also known as phosphoinositide 3-kinase (PI3K) delta isoform or p110δ is an enzyme that in humans is encoded by the PIK3CD gene.

<span class="mw-page-title-main">GRB2</span> Protein-coding gene in the species Homo sapiens

Growth factor receptor-bound protein 2, also known as Grb2, is an adaptor protein involved in signal transduction/cell communication. In humans, the GRB2 protein is encoded by the GRB2 gene.

<span class="mw-page-title-main">Bruton's tyrosine kinase</span> Kinase that plays a crucial role in B cell development.

Bruton's tyrosine kinase, also known as tyrosine-protein kinase BTK, is a tyrosine kinase that is encoded by the BTK gene in humans. BTK plays a crucial role in B cell development.

<span class="mw-page-title-main">Tyrosine-protein kinase SYK</span>

Tyrosine-protein kinase SYK, also known as spleen tyrosine kinase, is an enzyme which in humans is encoded by the SYK gene.

An immunoreceptor tyrosine-based activation motif (ITAM) is a conserved sequence of four amino acids that is repeated twice in the cytoplasmic tails of non-catalytic tyrosine-phosphorylated receptors, cell-surface proteins found mainly on immune cells. Its major role is being an integral component for the initiation of a variety of signaling pathway and subsequently the activation of immune cells, although different functions have been described, for example an osteoclast maturation.

<span class="mw-page-title-main">Lymphocyte cytosolic protein 2</span> Protein-coding gene in the species Homo sapiens

Lymphocyte cytosolic protein 2, also known as LCP2 or SLP-76, is a signal-transducing adaptor protein expressed in T cells and myeloid cells and is important in the signaling of T-cell receptors (TCRs). As an adaptor protein, SLP-76 does not have catalytic functions, primarily binding other signaling proteins to form larger signaling complexes. It is a key component of the signaling pathways of receptors with immunoreceptor tyrosine-based activation motifs (ITAMs) such as T-cell receptors, its precursors, and receptors for the Fc regions of certain antibodies. SLP-76 is expressed in T-cells and related lymphocytes like natural killer cells.

<span class="mw-page-title-main">ITK (gene)</span> Protein-coding gene in the species Homo sapiens

Tyrosine-protein kinase ITK/TSK also known as interleukin-2-inducible T-cell kinase or simply ITK, is a protein that in humans is encoded by the ITK gene. ITK is a member of the TEC family of kinases and is highly expressed in T cells.

<span class="mw-page-title-main">CD5 (protein)</span> Protein-coding gene in the species Homo sapiens

CD5 is a cluster of differentiation expressed on the surface of T cells and in a subset of murine B cells known as B-1a. The expression of this receptor in human B cells has been a controversial topic and to date there is no consensus regarding the role of this receptor as a marker of human B cells. B-1 cells have limited diversity of their B-cell receptor due to their lack of the enzyme terminal deoxynucleotidyl transferase (TdT) and are potentially self-reactive. CD5 serves to mitigate activating signals from the BCR so that the B-1 cells can only be activated by very strong stimuli and not by normal tissue proteins. CD5 was used as a T-cell marker until monoclonal antibodies against CD3 were developed.

<span class="mw-page-title-main">Linker for activation of T cells</span> Protein-coding gene in the species Homo sapiens

The Linker for activation of T cells, also known as linker of activated T cells or LAT, is a protein involved in the T-cell antigen receptor signal transduction pathway which in humans is encoded by the LAT gene. Alternative splicing results in multiple transcript variants encoding different isoforms.

<span class="mw-page-title-main">PLCG1</span> Protein-coding gene in the species Homo sapiens

Phospholipase C, gamma 1, also known as PLCG1 and PLCgamma1, is a protein that in humans involved in cell growth, migration, apoptosis, and proliferation. It is encoded by the PLCG1 gene and is part of the PLC superfamily.

<span class="mw-page-title-main">CD3G</span> Protein-coding gene in the species Homo sapiens

T-cell surface glycoprotein CD3 gamma chain is a protein that in humans is encoded by the CD3G gene.

<span class="mw-page-title-main">B-cell linker</span> Mammalian protein found in Homo sapiens

B-cell linker (BLNK) protein is expressed in B cells and macrophages and plays a large role in B cell receptor signaling. Like all adaptor proteins, BLNK has no known intrinsic enzymatic activity. Its function is to temporally and spatially coordinate and regulate downstream signaling effectors in B cell receptor (BCR) signaling, which is important in B cell development. Binding of these downstream effectors is dependent on BLNK phosphorylation. BLNK is encoded by the BLNK gene and is also known as SLP-65, BASH, and BCA.

<span class="mw-page-title-main">FYB</span> Protein-coding gene in the species Homo sapiens

FYN binding protein (FYB-120/130), also known as FYB, ADAP, and SLAP-130 is a protein that is encoded by the FYB gene in humans. The protein is expressed in T cells, monocytes, mast cells, macrophages, NK cells, but not B cells. FYB is a multifunctional protein involved in post-activation T cell signaling, lymphocyte cytokine production, cell adhesion, and actin remodeling.

<span class="mw-page-title-main">TXK (gene)</span> Protein-coding gene in the species Homo sapiens

Tyrosine-protein kinase TXK is an enzyme that in humans is encoded by the TXK gene.

A non-receptor tyrosine kinase (nRTK) is a cytosolic enzyme that is responsible for catalysing the transfer of a phosphate group from a nucleoside triphosphate donor, such as ATP, to tyrosine residues in proteins. Non-receptor tyrosine kinases are a subgroup of protein family tyrosine kinases, enzymes that can transfer the phosphate group from ATP to a tyrosine residue of a protein (phosphorylation). These enzymes regulate many cellular functions by switching on or switching off other enzymes in a cell.

Kinetic-segregation is a model proposed for the mechanism of T-cell receptor (TCR) triggering. It offers an explanation for how TCR binding to its ligand triggers T-cell activation, based on size-sensitivity for the molecules involved. Simon J. Davis and Anton van der Merwe, University of Oxford, proposed this model in 1996. According to the model, TCR signalling is initiated by segregation of phosphatases with large extracellular domains from the TCR complex when binding to its ligand, allowing small kinases to phosphorylate intracellular domains of the TCR without inhibition. Its might also be applicable to other receptors of the Non-catalytic tyrosine-phosphorylated receptors family such as CD28.

Non-catalytic tyrosine-phosphorylated receptors (NTRs), also called immunoreceptors or Src-family kinase-dependent receptors, are a group of cell surface receptors expressed by leukocytes that are important for cell migration and the recognition of abnormal cells or structures and the initiation of an immune response. These transmembrane receptors are not grouped into the NTR family based on sequence homology, but because they share a conserved signalling pathway utilizing the same signalling motifs. A signaling cascade is initiated when the receptors bind their respective ligand resulting in cell activation. For that tyrosine residues in the cytoplasmic tail of the receptors have to be phosphorylated, hence the receptors are referred to as tyrosine-phosphorylated receptors. They are called non-catalytic receptors, as the receptors have no intrinsic tyrosine kinase activity and cannot phosphorylate their own tyrosine residues. Phosphorylation is mediated by additionally recruited kinases. A prominent member of this receptor family is the T-cell receptor.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000115085 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000026117 - Ensembl, May 2017
  3. ↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. 1 2 3 Chen J, Moore A, Ringshausen I (2020). "ZAP-70 Shapes the Immune Microenvironment in B Cell Malignancies". Frontiers in Oncology. 10: 595832. doi: 10.3389/fonc.2020.595832 . PMC   7653097 . PMID   33194762.
  6. 1 2 3 Wang H, Kadlecek TA, Au-Yeung BB, Goodfellow HE, Hsu LY, Freedman TS, Weiss A (May 2010). "ZAP-70: an essential kinase in T-cell signaling". Cold Spring Harbor Perspectives in Biology. 2 (5): a002279. doi:10.1101/cshperspect.a002279. PMC   2857167 . PMID   20452964.
  7. ↑ Staal, Jens; Driege, Yasmine; Haegman, Mira; Borghi, Alice; Hulpiau, Paco; Lievens, Laurens; Gul, Ismail Sahin; Sundararaman, Srividhya; Gonçalves, Amanda; Dhondt, Ineke; Pinzón, Jorge H.; Braeckman, Bart P.; Technau, Ulrich; Saeys, Yvan; van Roy, Frans (2018-05-24). "Ancient Origin of the CARD–Coiled Coil/Bcl10/MALT1-Like Paracaspase Signaling Complex Indicates Unknown Critical Functions". Frontiers in Immunology. 9: 1136. doi: 10.3389/fimmu.2018.01136 . ISSN   1664-3224. PMC   5978004 . PMID   29881386.
  8. ↑ Au-Yeung BB, Shah NH, Shen L, Weiss A (April 2018). "ZAP-70 in Signaling, Biology, and Disease". Annual Review of Immunology. 36: 127–156. doi: 10.1146/annurev-immunol-042617-053335 . PMID   29237129.
  9. 1 2 3 Wang H, Kadlecek TA, Au-Yeung BB, Goodfellow HE, Hsu LY, Freedman TS, Weiss A (May 2010). "ZAP-70: an essential kinase in T-cell signaling". Cold Spring Harbor Perspectives in Biology. 2 (5): a002279. doi:10.1101/cshperspect.a002279. PMC   2857167 . PMID   20452964.
  10. ↑ Fasbender F, Claus M, Wingert S, Sandusky M, Watzl C (2017). "Differential Requirements for Src-Family Kinases in SYK or ZAP70-Mediated SLP-76 Phosphorylation in Lymphocytes". Frontiers in Immunology. 8: 789. doi: 10.3389/fimmu.2017.00789 . PMC   5500614 . PMID   28736554.
  11. ↑ Liu, Yini; Wang, Yangfeng; Yang, Jule; Bi, Yongyi; Wang, Hong (August 2018). "ZAP-70 in chronic lymphocytic leukemia: A meta-analysis". Clinica Chimica Acta. 483: 82–88. doi:10.1016/j.cca.2018.04.026. PMID   29680229. S2CID   5040894.
  12. ↑ Chiorazzi N, Rai KR, Ferrarini M (February 2005). "Chronic lymphocytic leukemia". The New England Journal of Medicine. 352 (8): 804–15. doi:10.1056/NEJMra041720. PMID   15728813.
  13. ↑ Tsokos GC (December 2011). "Systemic lupus erythematosus". The New England Journal of Medicine. 365 (22): 2110–21. doi:10.1056/NEJMra1100359. PMID   22129255.
  14. 1 2 3 4 Shirkani A, Shahrooei M, Azizi G, Rokni-Zadeh H, Abolhassani H, Farrokhi S, et al. (January 2017). "Novel Mutation of ZAP-70-related Combined Immunodeficiency: First Case from the National Iranian Registry and Review of the Literature". Immunological Investigations. 46 (1): 70–79. doi:10.1080/08820139.2016.1214962. PMID   27759478. S2CID   30518855.
  15. ↑ Lupher ML, Reedquist KA, Miyake S, Langdon WY, Band H (September 1996). "A novel phosphotyrosine-binding domain in the N-terminal transforming region of Cbl interacts directly and selectively with ZAP-70 in T cells". The Journal of Biological Chemistry. 271 (39): 24063–8. doi: 10.1074/jbc.271.39.24063 . PMID   8798643.
  16. ↑ Meng W, Sawasdikosol S, Burakoff SJ, Eck MJ (March 1999). "Structure of the amino-terminal domain of Cbl complexed to its binding site on ZAP-70 kinase". Nature. 398 (6722): 84–90. Bibcode:1999Natur.398...84M. doi:10.1038/18050. PMID   10078535. S2CID   4411124.
  17. ↑ Han J, Kori R, Shui JW, Chen YR, Yao Z, Tan TH (December 2003). "The SH3 domain-containing adaptor HIP-55 mediates c-Jun N-terminal kinase activation in T cell receptor signaling". The Journal of Biological Chemistry. 278 (52): 52195–202. doi: 10.1074/jbc.M305026200 . PMID   14557276.
  18. ↑ Neumeister EN, Zhu Y, Richard S, Terhorst C, Chan AC, Shaw AS (June 1995). "Binding of ZAP-70 to phosphorylated T-cell receptor zeta and eta enhances its autophosphorylation and generates specific binding sites for SH2 domain-containing proteins". Molecular and Cellular Biology. 15 (6): 3171–8. doi:10.1128/mcb.15.6.3171. PMC   230549 . PMID   7760813.
  19. ↑ Pelosi M, Di Bartolo V, Mounier V, Mège D, Pascussi JM, Dufour E, et al. (May 1999). "Tyrosine 319 in the interdomain B of ZAP-70 is a binding site for the Src homology 2 domain of Lck". The Journal of Biological Chemistry. 274 (20): 14229–37. doi: 10.1074/jbc.274.20.14229 . PMID   10318843.
  20. ↑ Thome M, Duplay P, Guttinger M, Acuto O (June 1995). "Syk and ZAP-70 mediate recruitment of p56lck/CD4 to the activated T cell receptor/CD3/zeta complex". The Journal of Experimental Medicine. 181 (6): 1997–2006. doi:10.1084/jem.181.6.1997. PMC   2192070 . PMID   7539035.
  21. ↑ Paz PE, Wang S, Clarke H, Lu X, Stokoe D, Abo A (June 2001). "Mapping the Zap-70 phosphorylation sites on LAT (linker for activation of T cells) required for recruitment and activation of signalling proteins in T cells". The Biochemical Journal. 356 (Pt 2): 461–71. doi:10.1042/bj3560461. PMC   1221857 . PMID   11368773.
  22. ↑ Perez-Villar JJ, Whitney GS, Sitnick MT, Dunn RJ, Venkatesan S, O'Day K, et al. (August 2002). "Phosphorylation of the linker for activation of T-cells by Itk promotes recruitment of Vav". Biochemistry. 41 (34): 10732–40. doi:10.1021/bi025554o. PMID   12186560.
  23. ↑ Lindholm CK, Henriksson ML, Hallberg B, Welsh M (July 2002). "Shb links SLP-76 and Vav with the CD3 complex in Jurkat T cells". European Journal of Biochemistry. 269 (13): 3279–88. doi:10.1046/j.1432-1033.2002.03008.x. PMID   12084069.
  24. ↑ Pacini S, Ulivieri C, Di Somma MM, Isacchi A, Lanfrancone L, Pelicci PG, et al. (August 1998). "Tyrosine 474 of ZAP-70 is required for association with the Shc adaptor and for T-cell antigen receptor-dependent gene activation". The Journal of Biological Chemistry. 273 (32): 20487–93. doi: 10.1074/jbc.273.32.20487 . PMID   9685404.

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