Search results

MAPRE2 (RP1 or EB2) is an evolutionarily conserved protein, which associates with the tips of growing microtubules, and regulates microtubule dynamics and their interactions with intracellular structures. The EB proteins regulate microtubule function through CLIP proteins. MAPRE2 shares noteworthy homology to the adenomatous polyposis coli (APC) protein-binding EB1 gene family. MAPRE2 is necessary for spindle symmetry during mitosis. MAPRE2 is believed to have a role in the tumorigenesis of colorectal cancers and the proliferative control of normal cells.

Apoptosis-Inducing Factor, Mitochondrion-Associated, 1 (AIFM1) is a mitochondrial protein which translocates to the nucleus once apoptosis has been initiated. AIFM1 causes DNA fragmentation and chromatin condensation and also triggers the release of cytochrome c and caspase-9 from mitochondria. Bcl-2 overexpression prevents the release of AIFM1 from mitochondria, but doesn’t block its apoptogenic activity.

Synaptic vesicle membrane docking and fusion is mediated by SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) located on the vesicle membrane (v-SNAREs) and the target membrane (t-SNAREs). The assembled v-SNARE/t-SNARE complex consists of a bundle of four helices, one of which is supplied by v-SNARE and the other three by t-SNARE. For t-SNAREs on the plasma membrane, the protein syntaxin supplies one helix and the protein encoded by this gene contributes the other two. Therefore, SNAP25 product is a presynaptic plasma membrane protein involved in the regulation of neurotransmitter release. The synaptosomal-associated protein (SNAP-25) is an essential component of the core complex that mediates presynaptic vesicle trafficking. Thus, SNAP-25 is directly involved in the release of neurotransmitters.

The acute phase plasma protein ORM1 synthesized by the liver mediates the interaction between blood cells and endothelial cells. In addition, together with haptoglobin and C reactive protein, ORM1 regulates the extravasation of the cells through infection and inflammation. Expression of ORM1 is induced by acute-phase stimulatory mediators such as bacterial lipopolysaccharides.

BAIAP2 is a ubiquitous regulator of the actin cytoskeleton. Controled by the Rho-family GTPases BAIAP2 facilitates filopodia development. BAIAP2 is expressed in the cytoplasm and binds small membrane-bound G-proteins to cytoplasmic effector proteins. BAIAP2 was identified as interacting with the dentatorubral-pallidoluysian atrophy gene, which is related to an autosomal dominant neurodegenerative disease.

Matrix metalloproteinase-7 (MMP-7) also known as matrilysin and PUMP (EC 3.4.24.23) cleaves a number of substrates including collagen types IV and X, elastin, fibronectin, gelatin, laminin and proteoglycans. MMP-7 is closely related to the stromelysin family members but is encoded by a different gene. MMP-7 is the smallest of all the MMPs consisting of a pro-peptide domain and a catalytic domain. It lacks the hemopexin-like domain common to other members of the MMPs. MMP-7 is secreted as a 28 kDa proenzyme and can be activated in vitro by organomercurials and trypsin and in vivo by MMP-3 to a 18 kDa active MMP-7 enzyme. Once activated, MMP-7 can activate pro-MMP-1 and pro-MMP-9 but not pro-MMP-2. MMP-7 is widely expressed having been reported in elevated levels in cycling endometrium as well as in colorectal cancers and adenomas, hepatocellular carcinomas, rectal carcinomas, and approximately 50% of gliomas.

PSMB10 is a member of the proteasome B-type family (T1B family) which is a 20S core beta subunit. The proteasome is a multicatalytic proteinase complex with an extremely ordered ring-shaped 20S core structure. This core structure is comprised of four rings of 28 non-identical subunits; two rings are composed of seven alpha subunits and two rings are composed of seven beta subunits. Proteasomes are circulated in eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. A crucial function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. PSMB10 gene expression is induced by INFg, and it replaces catalytic subunit 2 (proteasome beta 7 subunit) in the immunoproteasome.

Leukocyte-associated immunoglobulin-like receptor 2 (LAIR2) is a secreted, 131 amino acids protein which contains one IglikeC2 type domain, rendering it a member of the Ig superfamily. Even though one is secreted and one is membrane bound, the 2 LAIR proteins are assumed to have evolved from a common gene ancestor and seem to share similar adhesion profiles, suggesting that LAIR2 may compete with LAIR1 for ligand binding. LAIR2 was discovered by its similarity to LAIR1, which is an inhibitory receptor present on mononuclear leukocytes. The LAIR2 gene maps to a region of 19q13.4, dubbed the leukocyte receptor cluster, which contains 29 genes in the immunoglobulin superfamily, including LAIR1. The function of the LAIR2 protein is unknown, though it is assumed to be secreted and may help modulate mucosal tolerance.

The 26S proteasome is a multicatalytic proteinase complex with a well ordered structure composed of two complexes- a 20S core and a 19S regulator. PSMD11 is a non-ATPase subunit of the 19S regulator. The 20S core is composed of four rings of 28 non-identical subunits; two rings are composed of 7 alpha subunits and two rings are composed of 7 beta subunits. The 19S regulator is composed of a base that contains six ATPase subunits and two non-ATPase subunits, and a lid that contains up to ten non-ATPase subunits. Proteasomes are spread throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An indispensable function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.

Lymphocyte Antigen 9, also known as LY9 is a member of the SLAM family of immunomodulatory receptors, LY9 interacts with the adaptor molecule SAP . LY9 plays a part in adhesion reactions between T lymphocytes and accessory cells via homophilic interaction. LY9 promotes T-cell differentiation into a helper T-cell Th17 phenotype which leads to increased IL-17 secretion; the costimulatory activity requires SH2D1A. Furthermore it also promotes recruitment of RORC to the IL-17 promoter. LY9 is implicated in the maintenance of peripheral cell tolerance through serving as a negative regulator of the immune response. LY9 disables autoantibody responses as well as inhibits IFN-gamma secretion by CD4(+) T-cells. Moreover, LY9 negatively regulate the size of thymic innate CD8(+) T-cells and the development of invariant natural killer T (iNKT) cells. Systemic Lupus Erythematosus is one of the diseases which are associated with LY9.

Charged Multivesicular Body Protein 5 (CHMP5) is a member of the chromatin-modifying protein/charged multivesicular body protein (CHMP) family. These proteins comprise the ESCRT-III (endosomal sorting complex required for transport III), a complex involved in degradation of surface receptor proteins and development of endocytic multivesicular bodies (MVBs). Certain CHMPs have both nuclear and cytoplasmic/vesicular distributions, and one such CHMP the CHMP1A, is essential for both MVB formation and regulation of cell cycle progression.

Protein Phosphatase 2C alpha is a member of the PP2C family of Ser/Thr protein phosphatases. PP2C family members are known to be negative regulators of cell stress response pathways. This phosphatase dephosphorylates, and negatively regulates the activities of, MAP kinases and MAP kinase kinases. It has been shown to inhibit the activation of p38 and JNK kinase cascades induced by environmental stresses. This phosphatase can also dephosphorylate cyclin-dependent kinases, and thus may be involved in cell cycle control. Overexpression of this phosphatase is reported to activate the expression of the tumor suppressor gene TP53/p53, which leads to G2/M cell cycle arrest and apoptosis. Three alternatively spliced transcript variants encoding two distinct isoforms have been described.
Protein phosphatase 2C(PP2C?) is a Mn2+- or Mg2+-dependent protein serine/threonine phosphatase that is essential for regulating cellular stress response in eukaryotes.

LSM2 is a member of the snRNP Sm proteins family. Sm-like proteins are branded in several organisms based on sequence homology with the Sm protein family. Sm-like proteins hold the Sm sequence motif that is made up of 2 regions separated by a linker of variable length which folds as a loop. The Sm-like proteins are believed to create a steady heteromer present in tri-snRNP particles, which are vital for pre-mRNA splicing. LSM2 binds specifically to the 3'-terminal U-tract of U6 snRNA nad takes part in pre-mRNA splicing.

The proteasome is a multicatalytic proteinase complex with a highly assembled ring-shaped 20S core structure which is composed of 4 rings of 28 non-identical subunits, 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. Proteasomes are found throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. PSMA7 is part of the peptidase T1A family, that is a 20S core alpha subunit. PSMA7 interacts particularly with the hepatitis B virus X protein, a protein critical to viral replication. PSMA7 is involved in regulating hepatitis virus C internal ribosome entry site activity that is crucial for viral replication. PSMA7 is in charge for regulating the hypoxia-inducible factor-1alpha, a transcription factor important for cellular responses to oxygen tension. PSMA7 is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. PSMA7 interacts specifically with two subdomains of HIF-1alpha and inhibited the transactivation function of HIF-1alpha under both normoxic and hypoxia-mimicking conditions.

Proteasome subunit alpha type 4 (PSMA4) belongs to the peptidase T1A family, which is a 20S core alpha subunit. The proteasome is a multicatalytic proteinase complex with an extremely ordered ring-shaped 20S core structure. The core structure is comprised of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. PSMA4 is dispersed throughout eukaryotic cells at a high concentration and cleaves peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway.

Matrix metalloproteinases are a family of zinc and calcium-dependent endopeptidases that break down extracellular matrix proteins. The MMP9 is secreted as a 92kDa zymogen. Cleavage of ProMMP-9 results in the active enzyme, having a molecular weight of approximately 82kDa. MMP9 is composed of the following domains: a gelatin-binding domain consisting of three fibronectin type II units, a catalytic domain containing the zinc-binding site, a proline-rich type V collagen-homologous domain and a hemopexin-like domain. MMP9 is produced by the several cell types: monocytes, macrophages, neutrophils, keratinocytes, fibroblasts, osteoclasts and endothelial cells. MMP9 is involved in inflammatory responses, tissue remodeling, wound healing, tumor growth and metastasis. MMP9 may also play an important part in local proteolysis of the extracellular matrix and in leukocyte migration, as well as in bone osteoclastic resorption. MMP9 cleaves type IV and type V collagens into large C-terminal three quarter fragments and shorter N-terminal one quarter fragments. MMP9 can also degrade fibronectin but not laminin or Pz-peptide.
MMP9 defects may be a cause of susceptibility to intervertebral disc disease (IDD), also known as lumbar disk herniation (LDH).

Vps20-associated 1 homolog (VTA1) is a member of the VTA1 family. The VTA1 protein is involved in the endosomal multivesicular bodies (MVB) pathway. Furthermore, VTA1 is interacts with CHMP1B, CHMP2A, CHMP5, VPS4B, KIAA0174 (IST1) and possibly CHMP3. VTA1 is believed to be a cofactor of VPS4A/B, which catalyzes membrane-associated ESCRT-III assemblies. In addition, VTA1 is involved in the sorting and down-regulation of EGFR and also in HIV-1 budding.

lysozyme G-like 2 and LYGH (LYG2), is a member of the glycosyl hydrolase 23 family. Lysozyme takes part in human innate immunity by causing bacterial cell lysis. LYG2 contains a SLT domain, a protein domain present in bacterial lytic transglycosylase (SLT) and in eukaryotic lysozymes (GEWL). SLT domain catalyzes the cleavage of the beta-1,4-glycosidic bond between N-acetylmuramic acid (MurNAc) and N-acetyglucosamine (GlcNAc).

Chromatin modifying protein 2A (CHMP2A) is a member of the SNF7 family and it is a component of the ESCRT III complex, which is required for MVBs (multivesicular bodies) formation and sorting of endosomal cargo proteins into MVBs.
The MVB pathway mediates release of transmembrane proteins into the lumen of the lysosome for degradation. The MVB pathway requires the sequential function of ESCRT-O, -I,-II and -III complexes. ESCRT-III proteins generally detach from the invaginating membrane before the ILV (intraluminal vesicles) is released. ESCRT-III proteins are thought to mediate the basic vesicle extrusion and/or membrane fission activities, probably in conjunction with the AAA ATPase VPS4.

Leukemia Inhibitory Factor also called LIF is a lymphoid factor that promotes long-term maintenance of embryonic stem cells by suppressing spontaneous differentiation. Leukemia Inhibitory Factor has several functions such as cholinergic neuron differentiation, control of stem cell pluripotency, bone & fat metabolism, mitogenesis of factor dependent cell lines & promotion of megakaryocyte production in vivo. Human and mouse LIF exhibit a 78% identity in its amino acid sequence.

Synaptobrevin 1(Vehicle-associated membrane, VAMP1) is one of the key proteins in the SNARE complex which is involved in regulated exocytosis. Synaptobrevin1 binds to t-SNAREs, syntaxin (STX) and SNAP25, after the fusion of synaptic vesicles to plasma membrane.

Galectin 3, or LGALS3, is a protein which belongs to the animal lectins family, that binds betagalactoside residues selectively. LGALS3 is originated and leaves cells through ectocytosis. The protein is capable of inhibition apoptosis and the development of cancer. Galectin 3 is found in epithelial tissues in organisms, it can be located in dendritic cells, Kupffer cells, macrophages etc. LGALS3 levels elevated when inflammation is generating, cell proliferation, trans-activation by viral proteins and cell differentiation.

Alpha 1-microglobulin (A1M) is a lipocalin superfamily member (kernal lipocalins). A1M is a low molecular weight protein component of plasma. A1M is distributed in plasma and extravascular compartments of all organs. Alpha-1 Microglobulin is found in mammals, birds, amphibians and fish. The primary sites of A1M synthesis are the liver and the kidney. Around the opening of the lipocalin pocket three lysyl residues are situated; those residues carry yellow-brown modification derived from the binding and degradation of heme and kynurenin (a tryptophan metabolite). A1-Microglobulin’s reductase and dehydrogenase have broad biological substrate specificity properties due to its’ free cysteine side-chain which is located in a flexible loop. Alpha-1-microglobulin is glycosylated by three separate carbohydrate chains: two complex carbohydrates which are N-linked to asparagines at residues 17 and 96, and the other simple carbohydrate which is O-linked to threonine at position 5. The carbohydrates comprise 22% of the total molecular mass of the protein. The glycosylation varies between species.
A1M exists in two forms- a free form and complexed to other macromolecules: in humans- complexed to immunoglobulin A (IgA), in rat- complexed to alpha-1-inhibitor-3. Free A1M is exceptionally heterogeneous in charge (therefore also known as protein HC), and is found tightly linked to a chromophore. The free Alpha-1-microglobulin is a monomeric protein composed of one 188 residue polypeptide and contains three cysteines, two of which (residues 75 and 173) form a conserved intra-molecular disulphide link. The chromophoric group is covalently bound to the free cysteine residue at position 34. A1M binds retinol as a major ligand, but this is probably distinct from its covalent chromophore.
Half of all human plasma A1M (approximately 0.03mg/ml) forms a 1:1 complex with about 5% of plasma immunoglobulin A. The resulting macromolecular complexes’ molecular weight is 200000, and a plasma concentration of 0.3mg/ml. The complex can exhibit both antibody activity and affect many of the biological actions of free Alpha-1-microglobulin.
Alpha-1-microglobulin was first discovered in pathological human urine.
It was suggested that A1M might be involved in tissue defense against reactive oxygen species, oxidation by heme and kynurenin. Evidence also suggests that A1M functions in the regulation of the immune system. Other functions include inhibition of stimulation of cultured lymphocytes by protein antigens; induction of cell division of lymphocytes, a mitogenic effect that can either be enhanced or inhibited by the action of other plasma components; inhibition of neutrophil granulocyte migration in vitro; and inhibition of chemotaxis.

The CTX family of proteins (including ASAM) are type I transmembrane proteins within the Ig superfamily, which localize to junctional complexes between endothelial and epithelial cells and may play a role in cell-cell adhesion. CLMP has a role in adipocyte differentiation and development of obesity. CLMP is required for normal small intestine development.