Antibody News

Troponin I Type 1 - Find me in your slow-twitch skeletal muscles

Wednesday, December 31, 2014 - 14:39

Troponin I is part of a heteromeric thin filament regulatory complex that is responsible for modulating skeletal and cardiac muscle contraction. Troponin complex consists of three subunits: troponin I (TnI), troponin T (TnT), and troponin C (TnC). Each of these subunits has a different role in the function of the complex. In particular, TnI is the inhibitory component, and confers calcium-sensitivity to the ATPase activity of the myofibril contractile apparatus within striated muscles. By blocking actin-myosin interactions, it regulates muscle relaxation. TnI is encoded by three different genes to produce isoforms that are preferentially expressed as follows: TnI Type 1 (skeletal-slow-twitch), TnI Type 2 (skeletal-fast-twitch), and TnI Type 3 (cardiac). As their names imply, TnI Types 1 and 2 are only expressed in either fast-twitch or slow-twitch skeletal muscle fibers, respectively.


Troponin I Type 2 - I stay with fast-twitch skeletal muscles only

Monday, December 29, 2014 - 14:28

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...

Troponin I Type 3 (TnI, cardiac)

Wednesday, December 24, 2014 - 09:59

Troponin I is part of a heteromeric thin filament regulatory complex that governs skeletal and cardiac muscle contraction. Troponin I is composed of three subunits: troponin I (TnI), troponin T (TnT), and troponin C (TnC), and each of these components plays a different functional role. For example, TnI is an inhibitory component, and confers calcium-sensitivity to the ATPase activity of the myofibril contractile apparatus within striated muscles. Through blocking actin-myosin interactions, TnI modulates muscle relaxation. TnI itself is actually encoded by three different genes which produce tissue-specific isoforms as follows: TnI Type 1 (skeletal-slow-twitch), TnI Type 2 (skeletal-fast-twitch), and TnI Type 3 (cardiac). As their nomenclature implies, TnI Types 1 and 2 are expressed solely in fast- or slow-twitch...

Do you see what I see? I c-Kit

Tuesday, December 23, 2014 - 11:28

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...

CD86 - I work in tandem with CD80

Monday, December 22, 2014 - 14:59

CD86 belongs to the immunoglobulin superfamily of proteins that drive innate and adaptive immune responses. It is an 80kD co-stimulatory molecule for the priming and activation of naive and memory T-cells, respectively. CD86 is expressed on activated B- and T- cells, monocytes/macrophages, dendritic cells, and astrocytes. Engagement of CD28 with B7-1 and B7-2 ligands on antigen-presenting cells (APCs) stimulates T-cell activation and triggering of key pro-inflammatory cytokine responses through NF-kB, while subsequent engagement of CTLA-4 (also known as CD152) with these same ligands results in response attenuation. CD86 has also been shown to be involved in immunoglobulin class-switching and triggering of NK cell-mediated cytotoxicity.

With their central function in immune...

CD80: A co-stimulator of T cell activation

Friday, December 19, 2014 - 12:55

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....

Collagen I: Tissue origin detection has begun

Thursday, December 18, 2014 - 14:47

The extracellular matrix (ECM) is the external framework found between individual cells that comprise higher order structures like tissues and organs. The ECM composition of vertebrates is dominated by a class of molecules known as collagens - each with unique features suited for a particular function and location. Collagen proteins are made up of three subunit polypeptides that vary in length. Through a unique repeated (Gly-X-Y) sequence, these components associate to form a structurally regular triple helix. Collagen type I is one of the most common collagen forms and is found in a wide variety of areas including skin, tendon, vascular ligature, organs, and bone. Because of collagen I’s basic and fundamental role in guiding ECM architecture, its identification and detection is useful in the classification and verification of tissue-specific origins, and sample tissue typing.


B-cell activating factor (B7H4, B7S1, immune co-stimulatory protein B7-H4)

Wednesday, December 17, 2014 - 14:30

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...

CD68 (Cluster of differentiation 68, GP110, LAMP4, SCARD1)

Monday, December 15, 2014 - 14:29

CD68 belongs to a growing family of hematopoietic mucin-like molecules known as lysosomal/endosomal-associated membrane glycoproteins (LAMPs). Other LAMP family members included leukosialin, stem cell antigen CD34, and GlyCAM-1. CD68 encodes a 110-kD transmembrane glycoprotein with high levels of expression in human monocytes and tissue macrophages. CD68 binds lectins through a heavily glycosylated extracellular domain. It has also been found to be a member of the scavenger receptor family, whose main purpose is to clear cell debris, regulate phagocytosis, and recruit macrophages. CD68 transcripts are absent or present at very low levels in many hematopoietic lines, but can be induced by exposure to phorbol myristic acid (PMA/TPA).

Horny et al employed the CD68 antibody to distinguish between normal and neoplastic human monocytes, mast cells, and macrophages1. Their findings provide valuable diagnostic...

PCNA (Proliferating cell nuclear antigen, polymerase delta auxiliary protein)

Friday, December 12, 2014 - 14:19

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).


FMS-like tyrosine kinase 3 (FLT3/FLK2)

Thursday, December 11, 2014 - 14:31

FLT3 is a Type III tyrosine kinase cell surface receptor found on primitive bone marrow stem cells. The FLT3 ligand is a hematopoietic growth factor that stimulates cells via a set of structurally related tyrosine kinase receptors.  This FLT3 Ligand promotes the differentiation of multiple hematopoietic cell lineages and is expressed as a non-covalently-linked dimer by T-cells, bone marrow, and thymic fibroblasts. Downstream events in the FLT3 pathway include the expansion of monocytes and immature dendritic cells, B-cell differentiation, natural killer (NK) cell development, and myeloid differentiation of hematopoietic stem cells.

Because FLT3 overexpression and mutations are highly associated with...

L-selectin (CD62L antigen, Leukocyte surface antigen Leu-8)

Wednesday, December 10, 2014 - 14:33

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...

Growth hormone (GH, somatotropin, hGH, pituitary growth hormone)

Tuesday, December 9, 2014 - 14:53

GH is a member of the large family of growth factors that includes prolactin, placental lactogens, proliferins, and somatolactin. Additionally, GH is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by somatotropic cells within the lateral wings of the anterior pituitary gland. Release of GH into the circulation is mediated by the concerted actions of the hypothalamic hormones-GH-releasing hormone (GHRH) and somatostatin (SST), as well as through signals from the periphery-ghrelin and leptin. At least four alternatively spliced isoforms of GH are known. It is a multipotent and fundamental peptide hormone that stimulates growth, cell reproduction, and regeneration (see Matsuzaki et al for review) 1. Body growth stimulation occurs through the primary pathway of stimulating the liver (and other tissues) to secrete IGF-1.


GAPDH: More than a housekeeping gene

Monday, December 8, 2014 - 14:41

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...

MMP24 (Matrix metalloproteinase-24, matrix metalloproteinase-25, MT5-MMP)

Thursday, December 4, 2014 - 14:37

MMP24 is an extracellular matrix (ECM) degradative peptidase enzyme that is a member of the large family of matrix metalloproteinases (MMP). Each MMP has a different substrate specificity, and the aberrant or derailed expression of these is strongly correlated with unregulated events such as tumor invasion, metastasis, angiogenesis, and arthritis. This is in contrast to the tightly controlled normal physiological processes such as tissue remodeling, reproduction, rebuilding, and embryonic development. Deregulation often occurs through the loss of negative checks. Most MMP's are secreted as inactive proteins which are activated upon cleavage by extracellular proteinases. However, this protein is unusual is that it belongs to the membrane-type MMP (MT-MMP) subfamily – it contains a potential transmembrane domain suggesting that proteins of this subfamily are expressed at the cell surface rather than secreted. MMP24 activates MMP2 by cleavage. MMP24 is...

B-cell activating factor (BAFF) - keep the level steady!

Wednesday, December 3, 2014 - 15:22

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...

GPNMB (glycoprotein non-metastatic melanoma protein B, osteoactivin)

Tuesday, December 2, 2014 - 15:19

GPNMB is a type I transmembrane glycoprotein with homology to the PMEL17 precursor, a melanocyte-specific protein. Two transcript variants encoding different isoforms exist.GPNMB is expressed in minimally (but not highly) metastatic human melanoma cell lines and xenografts and may be involved in the delay and reduction of metastatic potential and growth. GPNMB appears to promote migration, invasion, and metastasis of a wide array of tumor cells and is therefore a promising and emerging target for drug development. Fiorentini’s group in the University of Brescia recently published that GPNMB acts on several prostate cancer cell lines by upregulating the metalloproteinases MMP2 and MMP91.  It was originally discovered in bone cells and also appears to be linked to eye syndromes such as iris...

VEGF: Vascular endothelial growth factor

Monday, November 24, 2014 - 09:36

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).

TLR4 - A Guardian of Innate Immunity

Friday, November 21, 2014 - 09:16

Toll-like receptor 4 (TLR4) belongs to the family of Toll-like receptors (TLR), and plays a main role in pathogen recognition and innate immunity system activation. The TLR family members are highly conserved proteins that all contain a high degree of structural and functional homology in organisms from Drosophila all the way up to humans. TLRs regulate the cellular cytokine production required for efficient innate immunity development through their recognition of pathogen-associated molecular patterns (PAMPs) expressed across a wide range of ligands, including infectious agents. TLR4 recognizes the Gram-negative bacterial membrane component lipopolysaccharide (LPS).

Immunohistochemistry-Paraffin: TLR4 Antibody Immunohistochemistry-...

Ly6G Antibody - A Marker for Monocytes, Granulocytes and Neutrophils

Thursday, November 20, 2014 - 09:22

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. 

Ly-6G expression in mouse bone marrow FFPE tissue section IHCImmunohistochemistry-Paraffin: Ly-6G/Ly-6C Antibody (RB6-8C5) [...

TLR2 - I can recognize many foreign pathogens!

Tuesday, November 18, 2014 - 09:06

TLR2 is a member of the broad family of Toll-like receptors (TLR) that play an important role in pathogen recognition and innate immunity. TLRs, like other pattern recognition receptors (PRRs), recognize endogenous ligands released during cell or tissue damage (DAMPs) as well as exogenous, pathogen associated ligands from bacteria or viruses (PAMPs).  Upon recognition of a specific ligand, PRRs activate host defense processes including cytokine and inflammatory mediator secretion, and innate immune cell activation and proliferation.  TLR2 recognizes the bacterial cell wall component, peptidoglycan. Recent Studies

  • A TLR2 antibody expression profiling study published by Palladino et al uncovered detailed profiles for over a dozen TLR family members in rat male reproductive tract organs and tissues1.
  • A Dutch research group used a TLR2 antibody to create similar expression...

Beta-catenin - I am versatile!

Monday, November 17, 2014 - 09:01

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.

BAG3 - Hsp70 is my friend!

Friday, November 14, 2014 - 08:50

The BAG proteins are a large family of chaperone regulators governing a wide range of cell processes such as proliferation, survival, stress response, tumorigenesis, neuronal differentiation, growth arrest and apoptosis as reviewed in Takayama et al1. BAG proteins are co-chaperones that interact with several forms of the chaperone heat shock protein 70 (Hsp70) – the association allows them to both positively and negatively regulate Hsp70. Family members include BAG-1 and its various isoforms, BAG-1L, BAG2, BAG3, BAG4 (SODD), BAG5, and BAG6 (Scythe, BAT3). BAG3 is involved in chaperone-mediated selective autophagy. BAG3 antibody was used by Liao et al in their expression studies in human pancreatic cancer tissues and cell lines2. With the...

Factor VII - A Major Protein in Blood Coagulation

Friday, October 31, 2014 - 13:14

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.

There is nothing beta than PKC Alpha

Friday, October 31, 2014 - 12:38

cAMP-dependent protein kinase (PKA) is a Ser/Thr protein kinase that is highly conserved between species. Three distinct catalytic (C) subunits have been identified, designated C-alpha, C-beta and C-gamma, where C-alpha and C-beta are most closely related. PKA mediates a variety of diverse cellular responses (cell growth and proliferation, ion transport, triglyceride storage and metabolism regulation, embryonic development, and gene transcription) in virtually all eukaryotic systems via phosphorylation of a wide range of downstream target proteins in both they cytoplasm and nucleus. Elevation of cAMP triggers the following cascade of events: PKA translocation from the cytoplasm to the nucleus, transcription factor cAMP response element binding protein (CREB) phosphorylation, TFIIB binding to the TATA-box-binding protein TBP1, and lastly, phosphorylated CREB binding to the pol II transcription initiation complex.



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