May 15th, 2012
Disulfide bond formation is a pivotal step in the maturation and release of secretory proteins that are controlled by specific endoplasmic reticulum (ER) resident enzymes. An important element in this process is ERO (ER oxidoreduction), a glycosylated flavoenzyme tightly associated with oxidative protein folding that lacks the known ER retention motifs. ER resident protein 44kDa (ERp44) is an ER resident protein that mediates ERO1 localization in ER and thus prevents the secretion of unassembled cargo proteins with unpaired cysteine (1). The production of secretory proteins at the ER depends on a ready supply of energy and metabolites as well as close monitoring of the biochemical conditions that favor oxidative protein folding. ER oxidoreductases and chaperones fold nascent proteins into their export-competent three-dimensional structure. Interference with these protein folding enzymes leads to the accumulation of unfolded proteins within the ER lumen, causing an acute organellar stress that triggers the unfolded protein response (2). Ero1 alpha antibody studies have revealed expression is almost exclusively found on the mitochondria-associated membrane (MAM). The localization of ERO1-alpha on the MAM is dependent on oxidizing conditions within the ER. Chemical reduction of the ER environment, but not ER stress in general leads to release of ERO1 alpha from the MAM. In addition, the correct localization of ERO1alpha to the MAM also requires normoxic but not hypoxic conditions (3). ERO1 oxidizes protein disulfide isomerase (PDI), which, in turn, introduces disulfides into ER client proteins. To maintain an oxidized state, ERO1 couples disulfide transfer to PDI with reduction of molecular oxygen, forming hydrogen peroxide thus, ERO1 activity constitutes a potential source of ER-derived oxidative stress (4). Novus Biologicals offers a wide variety of tools to investigate the role of ERO1L in ER stress in the form of antibodies, recombinant protein, Western blot lysates and RNAi.
Tags: Endoplasmic Reticulum, ERO1B, ERO1B antibody, ERO1L, ERO1L antibody, Oxidative Stress, PDI, PDI antibody, Protein Folding
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers | No Comments »
May 14th, 2012
Epigenetic alterations have come to prominence in biomedical research. In particular, hypermethylation of CpG islands located in the promoter regions of tumor-suppressor genes is now firmly established as an important mechanism for gene inactivation in cancer. Polycomb group (PcG) proteins are epigenetic chromatin modifiers involved in gene silencing, cancer development and the maintenance of adult and embryonic stem cells. One of the most remarkable achievements in the field has also been the identification of the methyl-CpG-binding domain family of proteins, which provide mechanistic links between specific patterns of DNA methylation and histone modifications. Interest in non-allelic histone variants has been renewed, in part because of recent work on H3 (and other) histone variants. However, only in mammals do three non-centromeric H3 variants (H3.1, H3.2, and H3.3) exist (1). Epigenetic changes underlie not only normal, but also pathological development. Bmi1 is recognized as a member of the PcG family of proteins (2). The PcG proteins function within distinct multisubunit complexes and epigenetically regulate gene expression by altering chromatin states at specific promoters. In concordance with its role in stem cells, Bmi-1 has been proposed to maintain cancer stem cell populations (3).
Pluripotent embryonic stem cells (ESCs) have the potential to produce every type of cell in the human body. Pluripotency is a unique epigenetic state, in that ESCs can self-renew, while retaining the potential for multilineage differentiation. OCT4 is highly expressed in pluripotent cells and becomes silenced upon differentiation. Interestingly, the precise expression level of OCT4 determines the fate of embryonic stem cells (4). Nevertheless, further investigations are required to fully elucidate the underlying molecular mechanisms responsible for the maintenance and initiation of pluripotency. Novus Biologicals offers an extensive collection of reagents to investigate epigenetic alterations, including Histone H3.2 K23me2 antibody (NB21-1162), Bmi1 antibody (NBP1-96140) and OCT4 antibody (NB100-2379) and our entire EpiPlus™ line.
- PMID: 16212490
- PMID: 1922340
- PMID: 12714970, PMID: 14574365
- PMID: 19480567
Tags: Bmi1, Bmi1 antibody, Chromatin Modifiers, DNA Methylation, Embryonic Stem Cell Marker, Embryonic Stem Cells, histone modification, Histone Modifications, Histones study, OCT4, Oct4 antibody, pluripotent, Pluripotent Embryonic Stem Cells
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Cancer, Epigenetics, Stem Cells, Tumor | No Comments »
May 11th, 2012
Discovery of histone variants using highly specific antibodies has led to the emerging notion that alterations in histone modifications and further changes in chromatin structure are induced by exchange of histone variants. Covalent histone modifications and the incorporation of histone variants bring about changes in chromatin structure that in turn alter the gene expression. These modifications can be detected using highly specific antibodies, such as the Epi-Plus™ products from Novus.
Interest in non-allelic histone variants has been renewed, in part because of recent studies of H3 (and other) histone variants. However only in mammals do three non-centromeric histone H3 variants (H3.1, H3.2, and H3.3) exist. Studies have shown that the variants of histone H3 differ primarily in their chromatin deposition patterns and post- translational modifications (1). Additional studies using H3 antibodies have shown that the interplay among deposition of H3 variants likely participates in the functional organization of chromatin. Available literature suggests that dynamic replacement of histone variants plays an important role in genome remodeling during early development and that histone H3 proteins are highly conserved across all eukaryotes and are dynamically modified by post-translational modifications (2). Extreme conservation of known acetylation and methylation sites of lysines and arginines predicts that these post-translational modifications exist across the eukaryotes with canonical chromatin structures (3).
In a recent study using Histone H3 antibodies, methylated histone (H3) expressions in unexplained recurrent spontaneous abortion (URSA) and normal early pregnancy was found to be significantly lower (P < 0.0001) in URSA tissues than in controls as determined by immunohistochemistry and western blotting using Histone H3 antibodies (4), suggesting that methylation may cause URSA indicating the need for further work to explore the role of methylation in various disorders including cancer. Novus Biologicals offers a wide variety of study tools including antibodies, lysates, proteins and peptides for your research needs.
- PMID: 16212490
- PMID: 21998593
- PMID: 21910587
- PMID: 21606120
Tags: Chromatin Modifiers, EpiPlus, Histone H3, Histone H3 antibody
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Epigenetics | No Comments »
May 10th, 2012
Glial fibrillary acidic protein (GFAP) is the main intermediate filament protein in mature astrocytes, but also an important component of the cytoskeleton in astrocytes during development. Recent developments using GFAP antibodies in astrocyte biology, and the discovery of novel intermediate filament functions, have enticed interest in the function of GFAP. The structural role of GFAP in astrocytes has been widely accepted for a long time, but over the years, studies using GFAP antibodies have shown GFAP to be involved in astrocyte functions, during human brain development, aging and disease (1). Immunohistochemical analysis using GFAP antibodies revealed up regulation of GFAP protein in older mice compared to their young counter parts in neurodegenerative disorders suggesting astrogliosis due to initial neurodegeneration (2). As a member of the cytoskeletal protein family, GFAP is thought to be important in modulating astrocyte motility and shape by providing structural stability to astrocytic processes. In the central nervous system (CNS) of vertebrates, astrocytes become reactive and respond in a typical manner, termed astrogliosis. Astrogliosis is characterized by rapid synthesis of GFAP and is demonstrated by an increase in protein content or by immunostaining with GFAP antibody. Additionally, the major application of GFAP antisera is also used routinely in astrocyte identification in the CNS. Studies using GFAP antibodies showing that mice lacking GFAP are hypersensitive to cervical spinal injury caused by sudden acceleration of the head have provided more direct evidence for a structural role of GFAP (3). While the structure and function of GFAP has become more accepted, use of GFAP antibodies continue to be valuable in studying CNS injury, disease, and development. Novus Biologicals offers a wide range of products and tools for research studies, including antibodies, lysates and recombinant proteins.
- PMID: 21219963
- PMID: 21960009
- PMID: 9665584
Tags: Astrogliosis, Central Nervous System, Cytoskeletan, GFAP, GFAP antibody
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Neurodegeneration, Neuroscience | No Comments »
May 8th, 2012
The transcription factor beta protein 1 (BP1) is a member of the homeobox gene family and the distal-less subfamily. Expression of BP1 is highly tissue-specific and developmentally restricted. Among different human tissues, BP1 is found to be highly expressed in placenta, kidney and at lower levels in fetal liver (1). Such restricted pattern of expression is compatible with a specific gene function in development and/or differentiation. Transient transfection studies demonstrate that BP1 protein appears to act as a repressor of the human adult beta globin gene, through two silencers upstream of the beta globin gene (2,3). BP1 binding site sequence upstream of beta globin gene in Asian populations has been investigated for the polymorphism in the BP1 binding site upstream of beta globin gene, so as to provide the basis for exploration of relation between polymorphisms in the BP1 binding site and beta globin expression (4,5). Beta globin gene cluster polymorphisms are known to be strongly associated with severity of beta-thalassemia in the Asian populations (6). Recent studies also indicate that BP1 genes are dysregulated in various cancers and some new studies point to an important role for BP1, an isoform of DLX4 homeobox gene, in breast carcinogenesis and progression (7). Current research directed towards the elucidation of the role of BP1 in breast tumorogenesis holds a great promise in establishing BP1 as a novel target for drug therapy. Novus Biologicals offers an extensive selection of BP1 study tools, for Western blots, ELISA, IHC and RNAi including highly specific antibodies with reactivity against different species.
- PMID: 11909945
- PMID: 10087993
- PMID: 15308321
- PMID: 22040981
- PMID: 15551156
- PMID: 17894837
- PMID: 20877436
Tags: beta-thalassemia, BP1, BP1 antibody, Breast Cancer, Breast Cancer Antibodies, DLX4, DLX4 antibody
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Cancer, Transcription Regulation, Tumor | No Comments »
May 7th, 2012
Reactive oxygen species, ROS, are beneficially involved in many signaling pathways that control development and maintain cellular homeostasis. In physiological conditions, a tightly regulated redox balance protects cells from injurious ROS activity, altered balance leads to various pathological conditions including cancer. MAP17 is a small 17-kDa non-glycosylated membrane protein that is overexpressed in many tumors of different origins, including carcinomas. Antibody studies have revealed that tumor cells overexpressing MAP17 show an increased tumoral phenotype associated with an increase in ROS. Increased MAP17 expression also results in enhanced proliferative capabilities both in presence or absence of contact inhibition, decreased apoptotic sensitivity and increased migration in cells. Malignant cell behavior induced by MAP17 is associated with an increased ROS production, and the treatment of MAP17-expressing cells with antioxidants results in a reduction of the tumorigenic properties. MAP17-dependent ROS increase and tumor malignancy are interdependent on its PDZ-binding domain, since disruption of its sequence by point mutations abolishes its ability to enhance ROS production and tumorigenesis (1). PDZ may represent the link between the cell membrane-where it interacts with MAP17-and other cytoplasmic proteins involved in biologic functions such as cell proliferation, differentiation, and ion transport (2). Interestingly, in non-tumor cells MAP17 increases ROS, resulting in senescence or apoptosis. Therefore, in tumor cells, MAP17 could be a marker for increased oxidative stress and could define new therapeutic approaches (3,4). We at Novus Biologicals offer a large number of MAP17 antibodies and support reagents to investigate the potential role in oxidative stress mediated tumorigenesis.
- PMID: 17548903
- PMID: 9461128
- PMID: 8701988
- PMID: 22465409
Tags: Antioxidants, MAP17, MAP17 antibody, Oxidative Stress, PDZ domain, Reactive Oxygen Species, ROS
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Apoptosis, Cancer, Tumor | No Comments »
May 1st, 2012
Epithelial-to-mesenchymal transition (EMT) is a critical event in the induction of cell motility and increased survival both under physiological situations like wound healing or development, as well as in malignant cells undergoing invasion and metastasis. Vimentin is an intermediate filament protein which is characteristically upregulated in cells undergoing EMT. Recent studies support the notion that vimentin functions as a positive regulator of EMT and upregulation of vimentin appears to be a prerequisite for EMT induction (1). Vimentin has been shown to be an important regulator of cell motility. In cell culture conditions, vimentin is upregulated at the wound edge in mammary epithelial cells and breast cancer cells (2,3). Additionally it has been shown that fibroblasts lacking vimentin migrate poorly, and display reduced mechanical stability, motility and directional migration towards different chemo-attractive stimuli (4). Furthermore, wounds in vimentin-deficient adult animals showed delayed migration of fibroblasts into the wound site and subsequently retarded contraction that correlated with a delayed appearance of myofibroblasts at the wound site (5). Vimentin has been recognized as a marker for EMT, although EMT is associated with several tumorigenic events, vimentin’s role in the underlying events mediating these processes remains unknown. By virtue of its overexpression in cancer and its association with tumor growth and metastasis, vimentin serves as an attractive potential target for cancer therapy; however, more research would be crucial to evaluate its specific role in cancer (6). Novus Biologicals offers a wide range of Vimentin related products such as poly and monoclonal antibodies, recombinant proteins, ELISA kits, protein lysates and RNAi products.
- PMID: 21686283
- PMID: 21057535
- PMID: 18281472
- PMID: 9625752
- PMID: 10852824
- PMID: 21637948
Tags: Breast Cancer, Breast Cancer Antibodies, Vimentin, Vimentin antibody, Wound healing
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Cancer, Tumor | No Comments »
April 30th, 2012
I began using the HSP60 antibody (NB110-57063) in June of 2010 and it worked well. I do not like to buy antibodies that have not been tested in the species for which I will use them, so I picked this antibody because it had already been tested in rat tissue. I split the antibody into 20ul aliquots and stored it at -20C. I first ran a Western blot with 15ug of a RIPA whole cell lystate from WKPT cells a rat kidney immortalized cell line derived from the S1 proximal tubule segment. I used a 10% SDS-PAGE gel and transferred to PVDF membrane for 1 hour in transfer buffer with 10% methanol. I then blocked with odyssey blocking buffer for 2 hours at RT. I probed with the primary antibody with a 1:1000 dilution over night at 4C, and have even gotten good signal with as little as 1:5000 dilution of the antibody. I incubated 1 hour with Licor goat anti rabbit 680nm secondary then imaged on an Odyssey scanner. I saw a band at about 60kDa, the blot was clear of any other containment bands. I used this antibody several times with similar result. I have only tried it with WKPT samples so far, but it worked great and I would recommend this antibody to others. I recently reused it and found I needed to use a more concentrated dilution (ie. 1:1000), however this is likely because it has been stored in -20 C for a year and a half.
This guest blog was submitted by Novus customer, Dana Freund of Colorado State University.
Tags: HSP60, HSP60 antibody, Western blot
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Heat Shock Proteins, Hypoxia | No Comments »
April 27th, 2012
Apoptosis is one of the main types of programmed cell death which involves a cascade of biochemical events leading to specific cell morphology characteristics and ultimately death of cells.
Caspases play crucial roles in modulating cellular signaling pathways involved in apoptosis and inflammation (1). Typically, caspase proteins consist of a prodomain, and large and small domains that are cleaved on activation. One class of prodomain is called caspase recruitment domain (CARD), common in caspase-1, -2, -4, -5, -9, -11, and -12, and some caspase-associated adapter proteins. The CARD–CARD interactions have also been known to participate in NF-kB signaling pathways in innate and adaptive immune responses including apoptosis (2). ASC (apoptosis-associated speck-like protein containing a CARD) or TMS 1 (target of methylation-induced silencing) ASC/TMS1 is a bipartite protein comprising two protein-protein interaction domains, a pyrin domain (PYD) and a caspase recruitment domain (CARD).
Proteins containing these domains play pivotal roles in regulating apoptosis and immune response pathways. Mutations in a number of PYD- and CARD-containing proteins have been linked to autoinflammatory diseases and cancer. Indeed, one of the ways in which ASC/TMS1 was identified was as a target of methylation-mediated silencing in breast cancer cells. ASC/TMS1 has been reported to functionally influence apoptosis, activation of inflammatory caspases and regulation of NF-kappa B (3). Novus Biologicals provides a variety of antibodies to ASC/TMS1 (NBP1-78977), CARD12 (NBP1-78979 & NBP1-78980) and NFKB p65 (NBP1-96138 & NBP1-96139), as well as proteins, peptides and RNAi to investigate the apoptotic pathways.
- PMID:15164013
- PMID:12101092
- PMID:14739594
Tags: ASC/TMS1, ASC/TMS1 antibody, Breast Cancer, Breast Cancer Antibodies, CARD 10, CARD 10 antibody, CARD 11, CARD 11 antibody, CARD 12, CARD 12 antibody, CARD 14, CARD 14 antibody, CARD 16, CARD 16 antibody, CARD 17, CARD 17 antibody, CARD 18, CARD 18 antibody, CARD 6, CARD 6 antibody, CARD 8, CARD 8 antibody, CARD 9, CARD 9 antibody, Caspase 1, Caspase 1 antibody, Caspase 11, Caspase 11 antibody, Caspase 12, Caspase 12 antibody, Caspase 2, Caspase 2 antibody, Caspase 4, Caspase 4 antibody, Caspase 5, Caspase 5 antibody, Caspase 9, Caspase 9 antibody, NFkB, NFkB antibody, NFkB p65, NFkB p65 antibody
Posted in Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Apoptosis, Cancer, Immunology, Inflammation | No Comments »
April 24th, 2012
S100A12 (Calgranulin C) belongs to the S100 family of calcium-binding proteins. The 20 members of this group share EF-hand domains which are involved in binding of calcium. S100A12 is expressed by granulocytes, whereas its expression by monocytes remains controversial (1). S100A12 is secreted by activated granulocytes (2). S100A12 is a ligand for the receptor for advanced glycation end products (RAGE) expressed on macrophages, lymphocytes and endothelium. RAGE mediates an up-regulation of the connective tissue growth factor IGFBP-rP2 (insulin-like growth factor binding protein-related protein 2), which is a potent inducer of angiogenesis (3). Additionally, RAGE has been shown to increase adhesion of granulocytes to stimulated endothelial cells (4). S100A12 serum levels might serve as a marker for local disease activity in different forms of arthritis as well. Patients with active arthritis revealed significantly higher S100A12 levels than healthy controls. The high local expression of S100A12 at the site of inflammation seems to be responsible for the correlating levels that are detected in serum (5). In different mouse models of inflammation including arthritis, blocking this interaction with soluble RAGE (sRAGE) and anti-S100A12 antibodies revealed clear anti-inflammatory effects (6). Further studies on the functional role of S100A12 in human arthritis have to prove the usefulness of new biological therapies that focus on pro-inflammatory activities of human S100A12. The expression of S100A12 in human arthritis provokes the question whether S100A12 protein and its interaction with RAGE might be a target for novel therapies. Novus Biologicals offers an extensive selection of S100A12 study tools, including S110A12 recombinant protein, cell lysate and highly specific antibodies with reactivity against different species.
- PMID: 10399917, 10973813
- PMID: 10726775
- PMID: 11316739
- PMID: 11854121
- PMID: 14644132
- PMID: 11581294
Tags: Arthritis, RAGE, RAGE antibody, S100A12, S100A12 antibody
Posted in Angiogenesis, Antibodies, Antibody catalog, Antibody database, Antibody suppliers, Cancer, Immunology, Inflammation, Rheumatoid Arthritis | No Comments »
