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4qt1
From Proteopedia
JAK3 kinase domain in complex with 1-[(3S)-1-isobutylsulfonyl-3-piperidyl]-3-(5H-pyrrolo[2,3-b]pyrazin-2-yl)urea
Structural highlights
DiseaseJAK3_HUMAN Defects in JAK3 are a cause of severe combined immunodeficiency autosomal recessive T-cell-negative/B-cell-positive/NK-cell-negative (T(-)B(+)NK(-) SCID) [MIM:600802. A form of severe combined immunodeficiency (SCID), a genetically and clinically heterogeneous group of rare congenital disorders characterized by impairment of both humoral and cell-mediated immunity, leukopenia, and low or absent antibody levels. Patients present in infancy recurrent, persistent infections by opportunistic organisms. The common characteristic of all types of SCID is absence of T-cell-mediated cellular immunity due to a defect in T-cell development.[1] [2] [3] [:][4] [5] [6] [7] [8] FunctionJAK3_HUMAN Non-receptor tyrosine kinase involved in various processes such as cell growth, development, or differentiation. Mediates essential signaling events in both innate and adaptive immunity and plays a crucial role in hematopoiesis during T-cells development. In the cytoplasm, plays a pivotal role in signal transduction via its association with type I receptors sharing the common subunit gamma such as IL2R, IL4R, IL7R, IL9R, IL15R and IL21R. Following ligand binding to cell surface receptors, phosphorylates specific tyrosine residues on the cytoplasmic tails of the receptor, creating docking sites for STATs proteins. Subsequently, phosphorylates the STATs proteins once they are recruited to the receptor. Phosphorylated STATs then form homodimer or heterodimers and translocate to the nucleus to activate gene transcription. For example, upon IL2R activation by IL2, JAK1 and JAK3 molecules bind to IL2R beta (IL2RB) and gamma chain (IL2RG) subunits inducing the tyrosine phosphorylation of both receptor subunits on their cytoplasmic domain. Then, STAT5A AND STAT5B are recruited, phosphorylated and activated by JAK1 and JAK3. Once activated, dimerized STAT5 translocates to the nucleus and promotes the transcription of specific target genes in a cytokine-specific fashion.[9] [10] [11] Publication Abstract from PubMedThe discovery of a novel series of pyrrolopyrazines as JAK inhibitors with comparable enzyme and cellular activity to tofacitinib is described. The series was identified using a scaffold hopping approach aided by structure based drug design using principles of intramolecular hydrogen bonding for conformational restriction and targeting specific pockets for modulating kinase activity. Scaffold hopping towards potent and selective JAK3 inhibitors: discovery of novel C-5 substituted pyrrolopyrazines.,de Vicente J, Lemoine R, Bartlett M, Hermann JC, Hekmat-Nejad M, Henningsen R, Jin S, Kuglstatter A, Li H, Lovey AJ, Menke J, Niu L, Patel V, Petersen A, Setti L, Shao A, Tivitmahaisoon P, Vu MD, Soth M Bioorg Med Chem Lett. 2014 Nov 1;24(21):4969-75. doi: 10.1016/j.bmcl.2014.09.031., Epub 2014 Sep 21. PMID:25262541[12] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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