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B-cell Linker
The B-cell linker protein is encoded by the ''BLNK'' gene and is an adaptor protein also known as SLP-65, BASH, and BCA. BLNK is expressed in B cells and macrophages and plays a large role in B cell receptor signalling, in a fashion analogous to the role its paralogue SLP-76 plays in T cell receptor signalling. As it has no known intrinsic enzymatic activity, the function of BLNK is to temporally and spatially coordinate and regulate signalling effectors downstream of the B cell receptor. Function The function of BLNK was first illustrated in BLNK deficient DT40 cells, a chicken B-cell line, which exhibited an abrogated intracellular calcium mobilisation response and impaired activation of MAP kinases p38, JNK, and to a lesser degree ERK upon B-cell receptor (BCR) activation as compared to wild type DT40 cells. In knockout mice, BLNK deficiency results in a partial block in B-cell development, and in humans BLNK deficiency results in a much more profound block in B-cell developm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucine Zipper
A leucine zipper (or leucine scissors) is a common three-dimensional structural motif in proteins. They were first described by Landschulz and collaborators in 1988 when they found that an enhancer binding protein had a very characteristic 30-amino acid segment and the display of these amino acid sequences on an idealized alpha helix revealed a periodic repetition of leucine residues at every seventh position over a distance covering eight helical turns. The polypeptide segments containing these periodic arrays of leucine residues were proposed to exist in an alpha-helical conformation and the leucine side chains from one alpha helix interdigitate with those from the alpha helix of a second polypeptide, facilitating dimerization. Leucine zippers are a dimerization motif of the bZIP (Basic-region leucine zipper) class of eukaryotic transcription factors. The bZIP domain is 60 to 80 amino acids in length with a highly conserved DNA binding basic region and a more diversified leucin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SH3KBP1
SH3 domain-containing kinase-binding protein 1 (synonyms - CIN85, in rodents - Ruk) is an adaptor protein that in humans is encoded by the ''SH3KBP1'' gene. Function CBL (MIM 165360) constitutively interacts with SH3 domain-containing proteins and, upon tyrosine phosphorylation, with SH2 domain-containing proteins. The SH3KBP1 gene encodes an 85-kD CBL-interacting protein that enhances tumor necrosis factor (MIM 191160)-mediated apoptotic cell death (Narita et al., 2001). upplied by OMIMref name="entrez"> Interactions SH3KBP1 has been shown to interact with B-cell linker, Grb2, SH3GLB2, SH3GL3, SH3GL2, BCAR1, Epidermal growth factor receptor, CBLB, Cbl gene, SOS1, CRK and PAK2 Serine/threonine-protein kinase PAK 2 is an enzyme that in humans is encoded by the ''PAK2'' gene. PAK2 is one of three members of Group I PAK family of serine/threonine kinases. The PAKs are evolutionary conserved. PAK2 and its cleaved fragment .... References Further reading * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NCK1
Cytoplasmic protein NCK1 is a protein that in humans is encoded by the ''NCK1'' gene. Gene The Nck (non-catalytic region of tyrosine kinase adaptor protein 1) belongs to the adaptor family of proteins. The nck gene was initially isolated from a human melanoma cDNA library using a monoclonal antibody produced against the human melanoma-associated antigen. The Nck family has two known members in human cells (Nck-1/Nckalpha and NcK2/NcKbeta), two in mouse cells (mNckalpha and mNckbeta/Grb4) and one in drosophila (Dock means dreadlocks-ortholog). The two murine gene products exhibit 68% amino acid identity to one another, with most of the sequence variation being located to the linker regions between the SH3 and SH2 domains, and are 96% identical to their human counterparts. While human nck-1 gene has been localised to the 3q21 locus of chromosome 3, the nck-2 gene can be found on chromosome 2 at the 2q12 locus. Function The protein encoded by this gene is one of the signaling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vav (protein)
Vav is a family of proteins involved in cell signalling. They act as guanine nucleotide exchange factors (GEFs) for small G proteins of the Rho family. GEF activity is mediated via module of tandem DH- PH domains. Vav proteins also appear to exhibit GEF-independent functions. Although it was originally thought that Vav proteins would only be present in multicellular organisms, Vav family proteins have been observed in Choanoflagellates. Function Some functions of the Vav protein are important for the immune system. Specifically the ability of Vav to change the cytoskeletal structure of lymphocytes, which is particularly used to "aim" cytokines towards bound pathogens or cells. In humans there are three Vav proteins: *Vav1 *Vav2 *Vav3 Guanine nucleotide exchange factor VAV3 is a protein that in humans is encoded by the ''VAV3'' gene. This gene is a member of the VAV gene family. The Vav (protein), VAV proteins are guanine nucleotide exchange factors (GEFs) for Rho family GTPas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruton's Tyrosine Kinase
Bruton's tyrosine kinase (abbreviated Btk or BTK), 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. Structure BTK contains five different protein interaction domains. These domains include an amino terminal pleckstrin homology (PH) domain, a proline-rich TEC homology (TH) domain, SRC homology (SH) domains SH2 and SH3, as well as a kinase domain with enzymatic activity. Function BTK plays a crucial role in B cell development as it is required for transmitting signals from the pre-B cell receptor that forms after successful immunoglobulin heavy chain rearrangement. It also has a role in mast cell activation through the high-affinity IgE receptor. Btk contains a PH domain that binds phosphatidylinositol (3,4,5)-trisphosphate (PIP3). PIP3 binding induces Btk to phosphorylate phospholipase C, which in turn hydrolyzes PIP2, a phosphatidylinositol, into two second mess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PLCG2
1-Phosphatidylinositol-4,5-bisphosphate phosphodiesterase gamma-2 is an enzyme that in humans is encoded by the ''PLCG2'' gene. Function Enzymes of the phospholipase C family catalyze the hydrolysis of phospholipids to yield diacylglycerols and water-soluble phosphorylated derivatives of the lipid head groups. A number of these enzymes have specificity for phosphoinositides. Of the phosphoinositide-specific phospholipase C enzymes, C-beta is regulated by heterotrimeric G protein-coupled receptors, while the closely related C-gamma-1 (PLCG1; MIM 172420) and C-gamma-2 enzymes are controlled by receptor tyrosine kinases. The C-gamma-1 and C-gamma-2 enzymes are composed of phospholipase domains that flank regions of homology to noncatalytic domains of the SRC oncogene product, SH2 and SH3. upplied by OMIMref name="entrez" /> Interactions PLCG2 has been shown to interact with: * Bruton's tyrosine kinase, * GAB2, * LYN, * PTPN11, and * SHC1 SHC-transforming protein 1 is a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD79A
Cluster of differentiation CD79A also known as B-cell antigen receptor complex-associated protein alpha chain and MB-1 membrane glycoprotein, is a protein that in humans is encoded by the CD79A gene. The CD79a protein together with the related CD79b protein, forms a dimer associated with membrane-bound immunoglobulin in B-cells, thus forming the B-cell antigen receptor (BCR). This occurs in a similar manner to the association of CD3 with the T-cell receptor, and enables the cell to respond to the presence of antigens on its surface. It is associated with agammaglobulinemia-3. Gene The mouse CD79A gene, then called mb-1, was cloned in the late 1980s, followed by the discovery of human CD79A in the early 1990s. It is a short gene, 4.3 kb in length, with 5 exons encoding for 2 splice variants resulting in 2 isoforms. CD79A is conserved and abundant among ray-finned fish (actinopterygii) but not in the evolutionarily more ancient chondrichthyes such as shark. The occurrence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoreceptor Tyrosine-based Activation Motif
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. Structure The motif contains a tyrosine separated from a leucine or isoleucine by any two other amino acids, giving the signature YxxL/I. Two of these signatures are typically separated by between 6 and 8 amino acids in the cytoplasmic tail of the molecule (YxxL/Ix(6-8)YxxL/I). However, it is worth noting that in various sources, this consensus sequence differs, mainly in the number of amino acids between individual signatures. Apart from ITAMs which have the structure described above, there is also a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SH2 Domain
The SH2 (Src Homology 2) domain is a structurally conserved protein domain contained within the Src oncoprotein and in many other intracellular signal-transducing proteins. SH2 domains allow proteins containing those domains to dock to phosphorylated tyrosine residues on other proteins. SH2 domains are commonly found in adaptor proteins that aid in the signal transduction of receptor tyrosine kinase pathways. Background SH2 is conserved by signalization of protein tyrosine kinase, which are binding on phosphotyrosine (pTyr). In the human proteome the class of pTyr-selective recognition domains is represented by SH2 domains. The N-terminal SH2 domains of cytoplasmic tyrosine kinase was at the beginning of evolution evolved with the occurrence of tyrosine phosphorylation. At the beginning it was supposed that, these domains serve as a substrate for their target kinase. Protein-protein interactions play a major role in cellular growth and development. Modular domains, which are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
