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TEC (gene)
Tyrosine-protein kinase Tec is a tyrosine kinase that in humans is encoded by the ''TEC'' gene. Tec kinase is expressed in hematopoietic, liver, and kidney cells and plays an important role in T-helper cell processes. Tec kinase is the name-giving member of the Tec kinase family, a family of non-receptor protein-tyrosine kinases. Structure Tec kinase contains five protein interaction domains. The characteristic feature of Tec family kinases is a pleckstrin homology (PH) domain on the N-terminus of the molecule followed by a Tec homology (TH) domain. The TH domain of Tec kinase contains a Btk homology (BH) motif and two proline-rich (PR) regions. The other protein interaction domains of Tec kinase include Src homology (SH) domains SH2 and SH3 and a kinase domain with enzymatic activity. ''TEC'' produces two protein isoforms that differ in the SH3 domain through alternative splicing. Type IV isoform has a full length SH3 domain and is predominately expressed in hematopoietic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrosine Kinase
A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases belong to a larger class of enzymes known as protein kinases which also attach phosphates to other amino acids such as serine and threonine. Phosphorylation of proteins by kinases is an important mechanism for communicating signals within a cell (signal transduction) and regulating cellular activity, such as cell division. Protein kinases can become mutated, stuck in the "on" position, and cause unregulated growth of the cell, which is a necessary step for the development of cancer. Therefore, kinase inhibitors, such as imatinib and osimertinib, are often effective cancer treatments. Most tyrosine kinases have an associated protein tyrosine phosphatase, which removes the phosphate group. Reaction Protein kinases are a group of enzymes that possess a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterotrimeric G-protein
Heterotrimeric G protein, also sometimes referred to as the ''"large" G proteins'' (as opposed to the subclass of smaller, monomeric small GTPases) are membrane-associated G proteins that form a heterotrimeric complex. The biggest non-structural difference between heterotrimeric and monomeric G protein is that heterotrimeric proteins bind to their cell-surface receptors, called G protein-coupled receptors, directly. These G proteins are made up of ''alpha'' (α), ''beta'' (β) and ''gamma'' (γ) subunits. The alpha subunit is attached to either a GTP or GDP, which serves as an on-off switch for the activation of G-protein. When ligands bind a GPCR, the GPCR acquires GEF ( guanine nucleotide exchange factor) ability, which activates the G-protein by exchanging the GDP on the ''alpha'' subunit to GTP. The binding of GTP to the ''alpha'' subunit results in a structural change and its dissociation from the rest of the G-protein. Generally, the ''alpha'' subunit binds membrane-bou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 17
Interleukin 17 family (IL17 family) is a family of pro-inflammatory cystine knot cytokines. They are produced by a group of T helper cell known as T helper 17 cell in response to their stimulation with IL-23. Originally, Th17 was identified in 1993 by Rouvier ''et al.'' who isolated IL17A transcript from a rodent T-cell hybridoma. The protein encoded by ''IL17A'' is a founding member of IL-17 family (see below). IL17A protein exhibits a high homology with a viral IL-17-like protein () encoded in the genome of T-lymphotropic rhadinovirus '' Herpesvirus saimiri''. In rodents, IL-17A is often referred to as CTLA8. The biologically active IL-17 interacts with type I cell surface receptor IL-17R. In turn, there are at least three variants of IL-17R referred to as IL17RA, IL17RB, and IL17RC. After binding to the receptor, IL-17 activates several signalling cascades that, in turn, lead to the induction of chemokines. Acting as chemoattractants, these chemokines recruit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IL17A
Interleukin-17A is a protein that in humans is encoded by the ''IL17A'' gene. In rodents, IL-17A used to be referred to as CTLA8, after the similarity with a viral gene (). Function The protein encoded by this gene is a proinflammatory cytokine produced by activated T cells. This cytokine regulates the activities of NF-kappaB and mitogen-activated protein kinases. This cytokine can stimulate the expression of IL6 and cyclooxygenase-2 ( PTGS2/COX-2), as well as enhance the production of nitric oxide (NO). Discovery IL-17A, often referred to as IL-17, was originally discovered at transcriptional level by Rouvier et al. in 1993 from a rodent T-cell hybridoma, derived from the fusion of a mouse cytotoxic T cell clone and a rat T cell lymphoma. Human and mouse IL-17A were cloned a few years later by Yao and Kennedy. Lymphocytes including CD4+, CD8+, gamma-delta T (γδ-T), invariant NKT and innate lymphoid cells (ILCs) are primary sources of IL-17A. Non-T cells, such as neut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Helper 17 Cell
T helper 17 cells (Th17) are a subset of pro-inflammatory T helper cells defined by their production of interleukin 17 (IL-17). They are related to T regulatory cells and the signals that cause Th17s to differentiate actually inhibit Treg differentiation. However, Th17s are developmentally distinct from Th1 and Th2 lineages. Th17 cells play an important role in maintaining mucosal barriers and contributing to pathogen clearance at mucosal surfaces; such protective and non-pathogenic Th17 cells have been termed as Treg17 cells. They have also been implicated in autoimmune and inflammatory disorders. The loss of Th17 cell populations at mucosal surfaces has been linked to chronic inflammation and microbial translocation. These regulatory Th17 cells can be generated by TGF-beta plus IL-6 in vitro. Differentiation Like conventional regulatory T cells (Treg), induction of regulatory Treg17 cells could play an important role in modulating and preventing certain autoimmune diseases. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrine, paracrine and endocrine signaling as immunomodulating agents. Cytokines include chemokines, interferons, interleukins, lymphokines, and tumour necrosis factors, but generally not hormones or growth factors (despite some overlap in the terminology). Cytokines are produced by a broad range of cells, including immune cells like macrophages, B lymphocytes, T lymphocytes and mast cells, as well as endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. They act through cell surface receptors and are especially important in the immune system; cytokines modulate the balance between humoral and cell-based immune responses, and they regulate the maturati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin-4 Receptor
The interleukin 4 receptor is a type I cytokine receptor. IL4R is its human gene. Function This gene encodes the alpha chain of the interleukin-4 receptor, a type I transmembrane protein that can bind interleukin 4 and interleukin 13 to regulate IgE antibody production in B cells. Among T cells, the encoded protein also can bind interleukin 4 to promote differentiation of Th2 cells. A soluble form of the encoded protein can be produced by an alternate splice variant or by proteolysis of the membrane-bound protein, and this soluble form can inhibit IL4-mediated cell proliferation and IL5 upregulation by T-cells. Allelic variations in this gene have been associated with atopy, a condition that can manifest itself as allergic rhinitis, sinusitis, asthma, or eczema. Two transcript variants encoding different isoforms, a membrane-bound and a soluble form, have been found for this gene. Interactions of IL-4 with TNFα promote structural changes to vascular endothelial cells, thus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IL-2 Receptor
The interleukin-2 receptor (IL-2R) is a heterotrimeric protein expressed on the surface of certain immune cells, such as lymphocytes, that binds and responds to a cytokine called IL-2. Composition IL-2 binds to the IL-2 receptor, which has three forms, generated by different combinations of three different proteins, often referred to as "chains": α (alpha) (also called IL-2Rα, CD25, or Tac antigen), β (beta) (also called IL-2Rβ, or CD122), and γ (gamma) (also called IL-2Rγ, γc, common gamma chain, or CD132); these subunits are also parts of receptors for other cytokines. The β and γ chains of the IL-2R are members of the type I cytokine receptor family. Structure-activity relationships of the IL-2/IL-2R interaction The three receptor chains are expressed separately and differently on various cell types and can assemble in different combinations and orders to generate low, intermediate, and high affinity IL-2 receptors. The α chain binds IL-2 with low affi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD28 Family Receptor
CD28 family receptors are a group of regulatory cell surface receptors expressed on immune cells. The CD28 family in turn is a subgroup of the immunoglobulin superfamily. Two family members, CD28 and ICOS, act as positive regulators of T cell function while another three, BTLA, CTLA-4 and PD-1 act as inhibitors. Ligands for the CD28 receptor family include B7 family proteins. CD28 receptors play a role in the development and proliferation of T cells. The CD28 receptors enhance signals from the T cell receptors (TCR) in order to stimulate an immune response and an anti-inflammatory response on regulatory T cells. Through the promotion of T cell function, CD28 receptors allow effector T cells to combat regulatory T cell-mediated suppression from adaptive immunity. CD28 receptors also elicit the prevention of spontaneous autoimmunity. Function CD28 receptors aid in other T cell processes such as cytoskeletal remodeling, production of cytokines and chemokines and intracellu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-cell Receptor
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. The TCR is composed of two different protein chains (that is, it is a heterodimer). In humans, in 95% of T cells the TCR consists of an alpha (α) chain and a beta (β) chain (encoded by '' TRA'' and ''TRB'', respectively), whereas in 5% of T cells the TCR consists of gamma and delta (γ/δ) chains (encoded by '' TRG'' and '' TRD'', respectively). This ratio changes during ontogeny and in diseased states (such as leukemia). It also differs between species. Orthologues of the 4 loci have been mapped in various species. Each locus can produce a va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD3 (immunology)
CD3 (cluster of differentiation 3) is a protein complex and T cell co-receptor that is involved in activating both the cytotoxic T cell (CD8+ naive T cells) and T helper cells (CD4+ naive T cells). It is composed of four distinct chains. In mammals, the complex contains a CD3γ chain, a CD3δ chain, and two CD3ε chains. These chains associate with the T-cell receptor (TCR) and the CD3-zeta (ζ-chain) to generate an activation signal in T lymphocytes. The TCR, CD3-zeta, and the other CD3 molecules together constitute the TCR complex. Structure The CD3γ, CD3δ, and CD3ε chains are highly related cell-surface proteins of the immunoglobulin superfamily containing a single extracellular immunoglobulin domain. A structure of the extracellular and transmembrane regions of the CD3γε/CD3δε/CD3ζζ/TCRαβ complex was solved with CryoEM, showing for the first time how the CD3 transmembrane regions enclose the TCR transmembrane regions in an open barrel. Containing aspa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interleukin 6
Interleukin 6 (IL-6) is an interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine. In humans, it is encoded by the ''IL6'' gene. In addition, osteoblasts secrete IL-6 to stimulate osteoclast formation. Smooth muscle cells in the tunica media of many blood vessels also produce IL-6 as a pro-inflammatory cytokine. IL-6's role as an anti-inflammatory myokine is mediated through its inhibitory effects on TNF-alpha and IL-1 and its activation of IL-1ra and IL-10. There is some early evidence that IL-6 can be used as an inflammatory marker for severe COVID-19 infection with poor prognosis, in the context of the wider coronavirus pandemic. Function Immune system IL-6 is secreted by macrophages in response to specific microbial molecules, referred to as pathogen-associated molecular patterns ( PAMPs). These PAMPs bind to an important group of detection molecules of the innate immune system, called pattern recognition receptors (PRRs) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
