Calcineurin

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Crystallographic structure of calcineurin heterodimer composed of the catalytic (PPP3CA) and regulatory (PPP3R1) subunits. Protein PPP3CA PDB 1aui.png
Crystallographic structure of calcineurin heterodimer composed of the catalytic (PPP3CA) and regulatory (PPP3R1) subunits.

Calcineurin (CaN) is a calcium and calmodulin dependent serine/threonine protein phosphatase (also known as protein phosphatase 3, and calcium-dependent serine-threonine phosphatase). [2] It activates the T cells of the immune system and can be blocked by drugs. Calcineurin activates nuclear factor of activated T cell cytoplasmic (NFATc), a transcription factor, by dephosphorylating it. The activated NFATc is then translocated into the nucleus, where it upregulates the expression of interleukin 2 (IL-2), which, in turn, stimulates the growth and differentiation of the T cell response. Calcineurin is the target of a class of drugs called calcineurin inhibitors, which include ciclosporin, voclosporin, pimecrolimus and tacrolimus.

Contents

Structure

Calcineurin is a heterodimer of a 61-kD calmodulin-binding catalytic subunit, calcineurin A and a 19-kD Ca2+-binding regulatory subunit, calcineurin B. There are three isozymes of the catalytic subunit, each encoded by a separate gene (PPP3CA, PPP3CB, and PPP3CC) and two isoforms of the regulatory, also encoded by separate genes (PPP3R1, PPP3R2).

protein phosphatase 3, catalytic subunit, alpha isozyme
Identifiers
Symbol PPP3CA
Alt. symbolsCALN, CALNA
NCBI gene 5530
HGNC 9314
OMIM 114105
RefSeq NM_000944
UniProt Q08209
Other data
EC number 3.1.3.16
Locus Chr. 4 q24
Search for
Structures Swiss-model
Domains InterPro
protein phosphatase 3, catalytic subunit, beta isozyme
Identifiers
Symbol PPP3CB
Alt. symbolsCALNB
NCBI gene 5532
HGNC 9315
OMIM 114106
RefSeq NM_021132
UniProt P16298
Other data
EC number 3.1.3.16
Locus Chr. 10 q22.2
Search for
Structures Swiss-model
Domains InterPro
protein phosphatase 3, catalytic subunit, gamma isozyme
Identifiers
Symbol PPP3CC
NCBI gene 5533
HGNC 9316
OMIM 114107
RefSeq NM_005605
UniProt P48454
Other data
EC number 3.1.3.16
Locus Chr. 8 p21.3
Search for
Structures Swiss-model
Domains InterPro
protein phosphatase 3, regulatory subunit B, alpha
Identifiers
Symbol PPP3R1
NCBI gene 5534
HGNC 9317
OMIM 601302
RefSeq NM_000945
UniProt P63098
Other data
EC number 3.1.3.16
Locus Chr. 2 p14
Search for
Structures Swiss-model
Domains InterPro
protein phosphatase 3, regulatory subunit B, beta
Identifiers
Symbol PPP3R2
NCBI gene 5535
HGNC 9318
OMIM 613821
RefSeq NM_147180
UniProt Q96LZ3
Other data
EC number 3.1.3.16
Locus Chr. 9 q31
Search for
Structures Swiss-model
Domains InterPro

Mechanism of action

When an antigen-presenting cell interacts with a T cell receptor on T cells, there is an increase in the cytoplasmic level of calcium, which activates calcineurin by binding a regulatory subunit and activating calmodulin binding. [3] Calcineurin induces transcription factors (NFATs) that are important in the transcription of IL-2 genes. IL-2 activates T-helper lymphocytes and induces the production of other cytokines. In this way, it governs the action of cytotoxic lymphocytes. The amount of IL-2 being produced by the T-helper cells is believed to influence the extent of the immune response significantly.

Clinical relevance

Rheumatic diseases

Calcineurin inhibitors are prescribed for adult rheumatoid arthritis (RA) as a single drug or in combination with methotrexate. The microemulsion formulation is approved by the U.S. Food and Drug Administration for treatment of severely active RA. It is also prescribed for: psoriatic arthritis, psoriasis, acute ocular Behçet's disease, juvenile idiopathic arthritis, adult and juvenile polymyositis and dermatomyositis, adult and juvenile systemic lupus erythematosus, adult lupus membranous nephritis, systemic sclerosis, aplastic anemia, steroid-resistant nephrotic syndrome, atopic dermatitis, severe corticosteroid-dependent asthma, severe ulcerative colitis, pemphigus vulgaris, myasthenia gravis, and dry eye disease, with or without Sjögren's syndrome (administered as ophthalmic emulsion). [4]

Schizophrenia

Calcineurin is linked to receptors for several brain chemicals including glutamate, dopamine and GABA. [5] An experiment with genetically-altered mice that could not produce calcineurin showed similar symptoms as in humans with schizophrenia: impairment in working memory, attention deficits, aberrant social behavior, and several other abnormalities characteristic of schizophrenia. [6]

Diabetes

Calcineurin along with NFAT, may improve the function of diabetics' pancreatic beta cells. [7] [8] Thus tacrolimus contributes to the frequent development of new diabetes following renal transplantation. [9]

Calcineurin/NFAT signaling is required for perinatal lung maturation and function. [10]

Organ transplantation

Calcineurin inhibitors such as tacrolimus are used to suppress the immune system in organ allotransplant recipients to prevent rejection of the transplanted tissue. [11]

Interactions

Calcineurin has been shown to interact with RCAN1 [12] and AKAP5. [13]

Related Research Articles

<span class="mw-page-title-main">Immunosuppressive drug</span> Drug that inhibits activity of immune system

Immunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are drugs that inhibit or prevent the activity of the immune system.

<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.

Stuart L. Schreiber is a scientist at Harvard University and co-founder of the Broad Institute. He has been active in chemical biology, especially the use of small molecules as probes of biology and medicine. Small molecules are the molecules of life most associated with dynamic information flow; these work in concert with the macromolecules that are the basis for inherited information flow.

<span class="mw-page-title-main">FKBP</span>

The FKBPs, or FK506 binding proteins, constitute a family of proteins that have prolyl isomerase activity and are related to the cyclophilins in function, though not in amino acid sequence. FKBPs have been identified in many eukaryotes, ranging from yeast to humans, and function as protein folding chaperones for proteins containing proline residues. Along with cyclophilin, FKBPs belong to the immunophilin family.

Nuclear factor of activated T-cells (NFAT) is a family of transcription factors shown to be important in immune response. One or more members of the NFAT family is expressed in most cells of the immune system. NFAT is also involved in the development of cardiac, skeletal muscle, and nervous systems. NFAT was first discovered as an activator for the transcription of IL-2 in T cells but has since been found to play an important role in regulating many more body systems. NFAT transcription factors are involved in many normal body processes as well as in development of several diseases, such as inflammatory bowel diseases and several types of cancer. NFAT is also being investigated as a drug target for several different disorders.

<span class="mw-page-title-main">PPP2CA</span> Enzyme

Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform is an enzyme that is encoded by the PPP2CA gene.

<span class="mw-page-title-main">NFATC2</span> Protein-coding gene in the species Homo sapiens

Nuclear factor of activated T-cells, cytoplasmic 2 is a protein that in humans is encoded by the NFATC2 gene.

<span class="mw-page-title-main">PPP2R2A</span> Enzyme found in humans

Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform is an enzyme regulator that in humans is encoded by the PPP2R2A gene.

<span class="mw-page-title-main">Myosin-light-chain phosphatase</span>

Myosin light-chain phosphatase, also called myosin phosphatase (EC 3.1.3.53; systematic name [myosin-light-chain]-phosphate phosphohydrolase), is an enzyme (specifically a serine/threonine-specific protein phosphatase) that dephosphorylates the regulatory light chain of myosin II:

<span class="mw-page-title-main">AKAP5</span> Protein-coding gene in the species Homo sapiens

A-kinase anchor protein 5 is a protein that in humans is encoded by the AKAP5 gene.

<span class="mw-page-title-main">NFATC3</span> Protein-coding gene in the species Homo sapiens

Nuclear factor of activated T-cells, cytoplasmic 3 is a protein that in humans is encoded by the NFATC3 gene.

<span class="mw-page-title-main">NFATC4</span> Protein-coding gene in the species Homo sapiens

Nuclear factor of activated T-cells, cytoplasmic 4 is a protein that in humans is encoded by the NFATC4 gene.

<span class="mw-page-title-main">PPP3CB</span> Protein-coding gene in the species Homo sapiens

Serine/threonine-protein phosphatase 2B catalytic subunit beta isoform (PP2BB) is an enzyme that in humans is encoded by the PPP3CB gene.

<span class="mw-page-title-main">PPP3R1</span> Protein-coding gene in the species Homo sapiens

Calcineurin subunit B type 1 also known as protein phosphatase 2B regulatory subunit 1 is a protein that in humans is encoded by the PPP3R1 gene.

<span class="mw-page-title-main">CABIN1</span> Protein-coding gene in the species Homo sapiens

Calcineurin-binding protein cabin-1 is a protein that in humans is encoded by the CABIN1 gene.

<span class="mw-page-title-main">PPP3CC</span> Protein-coding gene in the species Homo sapiens

Serine/threonine-protein phosphatase 2B catalytic subunit gamma isoform (PP2BC) is an enzyme that in humans is encoded by the PPP3CC gene.

<span class="mw-page-title-main">PPP3R2</span> Protein-coding gene in the species Homo sapiens

Calcineurin subunit B type 2 is a protein that in humans is encoded by the PPP3R2 gene. Among its related pathways are MAPK signaling pathway and GPCR pathway. GO annotations related to this gene include calcium ion binding. An important paralog of this gene is CHP1.

<span class="mw-page-title-main">PPP3CA</span> Protein-coding gene in the species Homo sapiens

Serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform (PP2BA) is a protein that in humans is encoded by the PPP3CA gene.

<span class="mw-page-title-main">Protein phosphatase 2</span> Class of enzyme complexes

Protein phosphatase 2 (PP2), also known as PP2A, is an enzyme that in humans is encoded by the PPP2CA gene. The PP2A heterotrimeric protein phosphatase is ubiquitously expressed, accounting for a large fraction of phosphatase activity in eukaryotic cells. Its serine/threonine phosphatase activity has a broad substrate specificity and diverse cellular functions. Among the targets of PP2A are proteins of oncogenic signaling cascades, such as Raf, MEK, and AKT, where PP2A may act as a tumor suppressor.

Patrick G. Hogan is a cellular and molecular biologist who studies how cellular signaling leads to gene expression. He obtained his bachelor’s degree from Harvard University and a PhD in neurobiology from Harvard Medical School. In 2010, he moved to the La Jolla Institute for Immunology in San Diego as a Professor in the Division of Signaling and Gene Expression. He is a Founder and Member of the Scientific Advisory Board, CalciMedica Inc, La Jolla, CA.

References

  1. PDB: 1AUI ; Kissinger CR, Parge HE, Knighton DR, Lewis CT, Pelletier LA, Tempczyk A, Kalish VJ, Tucker KD, Showalter RE, Moomaw EW (December 1995). "Crystal structures of human calcineurin and the human FKBP12-FK506-calcineurin complex". Nature. 378 (6557): 641–4. Bibcode:1995Natur.378..641K. doi:10.1038/378641a0. PMID   8524402. S2CID   4337105.
  2. Liu L, Zhang J, Yuan J, Dang Y, Yang C, Chen X, Xu J, Yu L (March 2005). "Characterization of a human regulatory subunit of protein phosphatase 3 gene (PPP3RL) expressed specifically in testis". Mol. Biol. Rep. 32 (1): 41–5. doi:10.1007/s11033-004-4250-4. PMID   15865209. S2CID   43848098.
  3. Yamashita M, Katsumata M, Iwashima M, Kimura M, Shimizu C, Kamata T, Shin T, Seki N, Suzuki S, Taniguchi M, Nakayama T (June 2000). "T cell receptor-induced calcineurin activation regulates T helper type 2 cell development by modifying the interleukin 4 receptor signaling complex". J. Exp. Med. 191 (11): 1869–79. doi:10.1084/jem.191.11.1869. PMC   2213529 . PMID   10839803.
  4. "Pharmacology and side effects of cyclosporine and tacrolimus". UpToDate. 2014-04-10.
  5. Bannai H, Lévi S, Schweizer C, Inoue T, Launey T, Racine V, Sibarita JB, Mikoshiba K, Triller A (2009). "Activity-dependent tuning of inhibitory neurotransmission based on GABAAR diffusion dynamics". Neuron. 62 (5): 670–82. doi: 10.1016/j.neuron.2009.04.023 . PMID   19524526. S2CID   18512241.
  6. Miyakawa T, Leiter LM, Gerber DJ, Gainetdinov RR, Sotnikova TD, Zeng H, Caron MG, Tonegawa S (July 2003). "Conditional calcineurin knockout mice exhibit multiple abnormal behaviors related to schizophrenia". Proc. Natl. Acad. Sci. U.S.A. 100 (15): 8987–92. Bibcode:2003PNAS..100.8987M. doi: 10.1073/pnas.1432926100 . PMC   166425 . PMID   12851457.
  7. Heit JJ, Apelqvist AA, Gu X, Winslow MM, Neilson JR, Crabtree GR, Kim SK (September 2006). "Calcineurin/NFAT signalling regulates pancreatic beta-cell growth and function". Nature. 443 (7109): 345–9. Bibcode:2006Natur.443..345H. doi:10.1038/nature05097. PMID   16988714. S2CID   4397036.
  8. Heit JJ (October 2007). "Calcineurin/NFAT signaling in the beta-cell: From diabetes to new therapeutics". BioEssays. 29 (10): 1011–21. doi:10.1002/bies.20644. PMID   17876792. S2CID   21027866.
  9. Crutchlow MF, Bloom RD (2007). "Transplant-associated hyperglycemia: a new look at an old problem". Clin J Am Soc Nephrol. 2 (2): 343–55. doi: 10.2215/CJN.03671106 . PMID   17699434.
  10. Davé V, Childs T, Xu Y, Ikegami M, Besnard V, Maeda Y, Wert SE, Neilson JR, Crabtree GR, Whitsett JA (October 2006). "Calcineurin/Nfat signaling is required for perinatal lung maturation and function". J. Clin. Invest. 116 (10): 2597–609. doi:10.1172/JCI27331. PMC   1570374 . PMID   16998587.
  11. "Tacrolimus". New Zealand Formulary v81. 1 March 2019.
  12. Fuentes JJ, Genescà L, Kingsbury TJ, Cunningham KW, Pérez-Riba M, Estivill X, de la Luna S (July 2000). "DSCR1, overexpressed in Down syndrome, is an inhibitor of calcineurin-mediated signaling pathways". Hum. Mol. Genet. 9 (11): 1681–90. doi: 10.1093/hmg/9.11.1681 . PMID   10861295.
  13. Kashishian A, Howard M, Loh C, Gallatin WM, Hoekstra MF, Lai Y (October 1998). "AKAP79 inhibits calcineurin through a site distinct from the immunophilin-binding region". J. Biol. Chem. 273 (42): 27412–9. doi: 10.1074/jbc.273.42.27412 . PMID   9765270.

Further reading