Antibody News

The protein Troponin I is a component of the heteromeric protein complex responsible for regulating both skeletal and cardiac muscle contraction. Troponin complex is made up of three parts: troponin I (TnI), troponin T (TnT), and troponin C (TnC). Each of these proteins has a particular function. TnI is the inhibitory component that confers calcium-sensitivity to the ATPase activity of the myofibril contractile apparatus. By interfering with actin-myosin interactions, TnI regulates muscle relaxation. TnI exists in three tissue-specific isoforms: TnI Type 1 (skeletal-slow-twitch), TnI Type 2 (skeletal-fast-twitch), and TnI Type 3 (cardiac). As their designations suggest, the TnI Types 1 and 2 are expressed only in fast- or slow-twitch skeletal muscle fibers, respectively, while TnI Type 3 is found expressed in cardiac muscle...

The c-Kit (CD117) proto-oncogene is a 145 kD receptor tyrosine kinase family closely related to platelet-derived growth factor receptor (PDGFR). It is a transmembrane receptor and the cellular homolog of the HZ4-feline sarcoma virus transforming gene (v-Kit). c-Kit is expressed on hematopoietic stem cells (multipotent hematopoietic stem cells, myeloid and/or erythroid lineage progenitors, and T-and B- cell precursors), mast cells, and acute myeloid leukemia (AML) cells. c-Kit regulates a variety of biological responses such as chemotaxis, cell proliferation, apoptosis, and adhesion. Mutations in c-Kit have been implicated in tumor growth and progression in various cancers. In mice, because c-Kit is identical to the W locus protein, it is integral to mast cell development and hematopoiesis. The c-Kit receptor (KL) ligand has been identified and is encoded by the murine steel (SI) locus.

Studies with the...

CD80 is a 60kD single chain type I transmembrane glycoprotein that is a member of the immunoglobulin family. CD80 is expressed on activated B- and T-lymphocytes, as well as a subpopulation of previously activated B-cells, but not on the majority of resting B-cells in peripheral blood. It is also found constitutively expressed on dendritic cells and macrophages.  CD80 and CD86 are both ligands for two structurally similar molecules expressed on T-lymphocytes - CD28 and CTLA4/CD152. Binding to these molecules is a potent co-stimulatory CD3 complex-dependent signal for T-lymphocyte activation, cytokinse production, and T-cell tolerance establishment. The roles of co-stimulatory (CD28) and co-inhibitory (CTLA4) molecules in T-cell receptor (TCR) signaling are nicely published by Chen in a Nature Reviews in Immunology1....

B7H4 is a co-stimulatory protein though to function as a negative regulator of T-cell mediated immunity by blocking proliferation, cell cycle progression and interleukin-2 (IL-2) production. Because B7H4-deficient mice are only minimally affected, it appears that B7H4 is involved in fine tuning of the T-cell mediated immune response. B7H4 is expressed on activated T-cells, B-cells, monocytes, and dendritic cells and exists in three different isoforms. Its aberrant expression has been associated with a variety of cancers such as lung, breast, and ovary, and it may hold promise as a prognostic marker for renal cell carcinoma (RCC). Sarafian et al examine the expression profile of human blood group antigenic determinants such as B7H4 in normal human tissues1.

More immunology profiling studies from another...

PCNA is a nuclear protein essential for DNA replication as well as DNA excision and mismatch repair pathways. It coordinates the recruitment and association of needed components during both of these processes, both of which are essential for cell cycle regulation and cell response to stress.  Through the symmetric association of three identical monomers, PCNA forms a toroidal, ring-shaped structure that encircles DNA. This serves as the scaffold upon which polymerases and other proteins dock and associate.  It has been demonstrated that PCNA binds directly to downstream signaling molecules such as CDK inhibitor p21, endonucleases Fen1 and XPG, and DNA cytosine 5-methyltransferase (MCMT).

...

L-selectin is a member of the selectin family of glycoprotein adhesion and homing receptors that recognize sialyated carbohydrate groups and regulate lymphocyte-endothelial cell interactions. It is a type I transmembrane cell adhesion molecule (CAM) and is constitutively expressed on all classes of circulating leukocytes including lymphocytes (excluding memory T-cells), monocytes, and polymorphonuclear (PMN) cells. L-selectin is also expressed on bone marrow myeloid progenitor cells, erythroid precursor cells, and some thymocytes. Knockout mice studies implicate L-selectin in health and disease conditions – leukocyte recruitment to lymph nodes, acute and chronic inflammation, etc.  

A detailed overview of the L-selectin signaling cascade (including currently...

GAPDH is a 146kD tetramer glycolytic pathway metabolic enzyme composed of four 30-40 kDa subunits. It is responsible for reversibly phosphorylating its substrate glyceraldehyde 3-phosphate within the glycolytic pathway.  Apart from its role in glycolysis, GAPDH may have other roles such as transcriptional activation. Due to its housekeeping role, GAPDH is highly expressed in almost all tissues, allowing its use as an internal loading control (traditionally for mRNA expression comparisons, but also in protein studies. The GAPDH antibody is an established standard as evidenced by its usage in a wide range of scientific research and published literature.  GAPDH is reported to bind to a variety of other proteins, including the amyloid precursor protein. Associations with actin and tubulin have also been reported. The protein may also have a role in the regulation of apoptosis. Shin et al employed the...

BAFF belongs to the tumor necrosis factor (TNF) family, and its downstream signaling plays a critical role in B-cell survival and maturation. BAFF overproduction is associated with a variety of autoimmune diseases. BAFF is the functional ligand for three receptors:
BAFF-R, transmembrane activator and calcium modulator (TACI), and B-cell maturation Ag (BCMA). Varzaneh et al extensively review the contributions of a huge array of interleukins (ILs), interferons, tumor necrosis factor alpha (TNFa), APRIL, and BAFF in common variable immunodeficiency (CVID) disease1. Their study maps in detail the profiles of various cytokines as well as outlines their therapeutic potential. Another recent autoimmune review from Lanteri‘s group examined the role of serum free light chains of immunoglobulins (sFLC) in systemic sclerosis (SSc)2.  Using a...

VEGF is homodimeric, disulfide-linked glycoprotein cytokine that serves as the ligand for FLT1 (VEGFR-1 receptor) and FLK1 (VEGFR-2 receptor) tyrosine kinases. It is a key modulator of physiological angiogenesis, vasculogenesis, and endothelial cell growth during basic developmental processes such as embryogenesis, skeletal growth, and reproductive functions. The VEGF ligand/receptor signaling system stimulates endothelial cell proliferation, blood vessel permeabilization, cell migration, and inhibition of apoptosis. There exist several widely expressed isoforms (VEGF189, VEGF165 and VEGF121) as well as some that are not as commonly found (VEGF206 and VEGF145). The basic VEGF189 isoform is cell-associated after secretion and is bound avidly by heparin and the extracellular matrix (ECM).

What is Ly6G?

Ly6G (Lymphocyte antigen 6 complex locus G6D) is a 21-25kD glycosylphosphatidylinositol (GPI)-linked differentiation antigen that is expressed by myeloid-derived cells in a tightly developmentally-regulated manner in the bone marrow. Monocytes express Ly6G transiently during bone marrow development, while Ly6G expression in granulocytes and peripheral neutrophils directly correlates with the cell’s level of differentiation and maturation. This hallmark makes Ly6G a good marker for these particular cell populations. Ly6G has also been implicated in the development of antitumor responses. 

Immunohistochemistry-Paraffin: Ly-6G/Ly-6C Antibody (RB6-8C5) [...

Beta-catenin is a cytosolic, 88 kDa intracellular protein associated with cell surface cadherin glycoproteins. It is a member of the larger calcium-dependent catenin family that includes alpha-catenin, beta-catenin, and gamma-catenin (also known as plakoglobin). Beta-catenin enters the nucleus to interact with TCF/LEF (Lymphoid enhancer factor-1) transcription factor family. It is normally inhibited by the GSK (glycogen synthase kinase) or CK1 (casein kinase 1) as phosphorylation of beta-catenin targets it for ubiquitin-mediated degradation.  The beta-catenin/TCF pathway is involved in T-cell development and differentiation and may be a target for immune and autoimmune disorders.

Factor VII (coagulation factor VII) is a 50 kD multidomain single chain plasma glycoprotein synthesized in the liver. It is a vitamin K-dependent serine protease essential for the extrinsic pathway of hemostasis, or blood coagulation. Factor VII circulates in the blood in a zymogen form that is converted to an active form (via factor IXa, factor Xa, factor XIIa, or thrombin). Rare bleeding disorders (RBDs) are rare within the general community, but present both a diagnostic and effective treatment challenge due to the highly variable range in clinical presentation and cause. Defects in Factor VII cause coagulopathy and hemorrhagic disease, which range in severity from mild tolerable events to acutely severe and repeated hemarthroses and life-threatening intracerebral hemorrhages.