Antibody News

Autophagy is a process by which cells degrade and recycle damaged organelles or misfolded proteins. These various cargo are engulfed in a double-membrane structure called the autophagosome. The autophagosome then fuses with the lysosome to facilitate the degradation of the cargo. This process requires the concerted effort of an extensive network of proteins. One of the early steps of autophagosome assembly is the formation of the large multimeric ATG12-ATG5-ATG16 complex. This complex acts as an E3 ligase during the lipidation of ATG8. ATG8 is then incorporated into the expanding autophagosomal membrane and facilitates the recruitment of core autophagy machinery and substrates targeted for degradation. ATG16L2 is an isoform of ATG16 whose function is still unclear. While the isoform ATG16L1 is essential for autophagy, ATG16L2 does not seem to be important (1). In an examination of ATG16L2...

The heat-shock protein 90 (HSP90) family is a group of highly conserved molecular chaperones with important functions in protein folding and in signal transduction. The HSP90 protein structure is so well conserved that some HSP90 antibodies are reactive with a broad range of species from humans to chickens (1). In humans there are 17 known genes encoding the HSP90 family members. The HSP90 family consists of 4 different classes: HSP90AA, HSP90AB, HSP90B, and TRAP. These classes are defined by their diversity of functions and sub cellular localization. HSP90 isoforms are known to localize to the cytosol, nucleoplasm, endoplasmic reticulum, mitochondria, and chloroplasts. HSP90 is an abundant protein that maintains cellular homeostasis by promoting the proper folding of hundreds of substrate proteins referred to as clients. These clients range from protein kinases to transcription factors making HSP90 an essential component of many...

Fms-like tyrosine kinase-3 (FLT3) is a Type III receptor tyrosine kinase expressed by hematopoietic progenitor cells. FLT3 is also sometimes referred to as FLK2 or CD135. The FLT3 protein exists in two states- membrane bound (160 kDa) and cytoplasmic (140 kDa) (1). The FLT3 ligand induces autophosphorylation of FLT3 which allows binding of scaffold and effector molecules. Activated FLT3 is capable of phosphorylating and activating PI3K, PLC-γ, Shc, Grb2, and Src (2). FLT3 signaling ultimately activates the AKT and MAPK pathways to promote cell growth and survival. Mutations in FLT3 account for nearly one third of acute myeloid leukemia (AML) cases. The most common FLT3 derangement in AML is an internal tandem duplication (ITD) in the juxtamembrane domain. FLT3-ITD causes constituent activation of FLT3 signaling. Other activating mutations have also been identified, suggesting an important role for FLT3 in leukemogenesis. FLT3 overexpression correlates with a poor...

Akt1 is one of three isoforms of Akt belonging to the AGC family of serine/threonine kinases (Akt1, Akt2, and Akt3). All Akt isoforms contain an N-terminal Plekstrin Homology (PH) domain, a C-terminal regulatory domain, and a central catalytic kinase domain (1). Akt is a major downstream target of the PI3-K signaling pathway. The Akt1 isoform is fully activated by phosphorylation at three sites- T308, T450, and S473. Akt1 resides in an inactive state due to intramolecular interactions between the PH domain and the kinase domain. PI3-K signaling induces a conformational change that exposes the active sites to allow phosphorylation and activation of Akt1 (1). Akt plays a variety of roles in normal cellular metabolism, growth, proliferation, and survival. It has also been implicated in malignancies as a driver of angiogenesis, migration, and invasion. Recent studies have begun to tease apart the signaling specificity of the three Akt isoforms. Akt1 is expressed in many...

TSC2 is a tumor suppressor gene that encodes a 200 kDa protein called tuberin. TSC2 heterodimerizes with TSC1 to form a complex with GTPase-activating protein (GAP) activity. The C-terminus of TSC2 contains the GAP domain responsible for this catalytic activity. The complex was first discovered through its role in the tumor-forming condition Tuberous Sclerosis. Mutations in TSC1 and TSC2 can either destabilize the complex or compromise the GAP activity. The TSC1-TSC2 complex acts as a GAP for the small G-protein Rheb, expressed ubiquitously throughout the body (1). Rheb inhibits mTOR signaling to downregulate protein synthesis and cell growth. Thus in the absence of TSC1-TSC2, mTOR signaling allows unchecked cellular growth and proliferation. TSC1-TSC2 acts as a nutrient sensor for amino acids, growth factors, hormones, etc. and mediates cell cycle progression. The TSC1-TSC2 complex can be phosphorylated at a number of sites that are either activating or inactivating....

TSC1 is a tumor suppressor gene that encodes a 130 kDa protein called hamartin. TSC1 was first identified as an oncogenic driver of Tuberous Sclerosis, a condition characterized by numerous benign tumors of the skin, brain, heart, and lungs. A mutation in TSC1 is responsible for the uncontrolled growth characteristic of these tumors. This discovery led to a greater understanding of the physiologic role of TSC1 as a negative cell cycle regulator. The distinct but related gene TSC2 encodes a 200 kDa protein called tuberin. TSC1 and TSC2 heterodimerize to form a complex that acts as a GTPase-activating protein (GAP) for the G-protein Rheb (1). Rheb is a member of the Ras family that inhibits mTORC1 signaling when activated by the TSC1-TSC2 complex. mTORC1 signaling promotes cell growth and proliferation and aberrant signaling promotes tumor formation. The TSC1-TSC2 complex acts as a sensor for levels of growth factors, amino acids, and other...

Human hepatocytes express important transport proteins that are responsible for the uptake and removal of organic anions from the blood. These proteins are members of the organic anion-transporting polypeptide (OATP) family and are essential for proper liver function. OATPs are encoded by the SLC21 gene family and contain 12 transmembrane alpha-helices and are primarily expressed in the liver. The OATP family transports endogenous substrates like bile salts and steroid hormones as well as exogenous molecules like anticancer drugs and imaging agents. This broad specificity makes OATPs an important research topic for understanding basic liver biology and for designing therapeutic and diagnostic strategies. Of particular importance is OATP8. Early studies of OATP8 used immunofluorescent staining with OATP8 antibodies to demonstrate basolateral localization in human hepatocytes (1). Additionally immunoblotting with...

c-Myc is a protein of the Myc family of transcription factors (c-Myc, B-Myc, L-Myc, N-Myc, and s-Myc) encoded by the MYC proto-oncogene. c-Myc was first discovered as the cellular homolog of the retroviral v-Myc oncogene. c-Myc is a transcription factor for genes involved in cell growth, proliferation, differentiation, and apoptosis. c-Myc contains a basic helix-loop-helix domain and a leucine zipper domain that allow for its heterodimerization with its binding partner Max. Myc/Max complexes are able to activate genes via the Myc transactivation domain (1). In healthy cells, c-Myc expression is tightly regulated by NFκB and other transcription control mechanisms. However, c-Myc translocations have been identified in numerous malignancies that allow deregulation and constitutive expression of c-Myc. c-Myc translocations account for almost 100% of Burkitt ’s lymphoma cases (2).  Translocations and mutations in c-Myc account for up to one seventh of all U.S. cancer...

R&D Systems' primary antibodies are made in house at our facility in Minneapolis, MN with the goal of creating the most specific and replicable lots of antibody available. From careful antigen design to in-house testing in multiple applications, the aim of R&D Systems is to maximize the specificity of each antibody and eliminate off target binding.  Going further, R&D Systems’ antibodies are repeatedly tested to ensure the industry’s best lot to lot reproducibility for a product you can count on in all of your experiments now, and later on in your project.

Flow cytometry requires primary antibodies conjugated to multiple fluorophores to allow multiplexing several targets to identify and characterize specific cell populations of interest.  Additionally, flow cytometry requires highly specific reagents that researchers can rely on because it is difficult to completely control for non-specific binding.  To address these...

Sterol regulatory element-binding proteins (SREBP) are important transcription factors regulating the synthesis and uptake of lipids including cholesterol. This essential role in lipid metabolism makes investigations into the functions SREBPs important for understanding metabolic disorders such as diabetes and may provide insight for future drug treatment strategies. SREBPs are basic helix-loop-helix (bHLH) leucine zipper transcription factors that bind to sterol response elements (SRE) to enhance the expression of target genes including LDL receptor and lipid synthesis genes. In humans there are two SREBP genes, SREBP1 and SREBP2. SREBP1 is expressed primarily in the liver while SREBP2 is ubiquitously expressed. SREBPs are synthesized as ER membrane proteins where they bind with SREBP cleavage-activating protein (SCAP), an important cholesterol sensor and transporter. This association with SCAP retains SREBP in...

The vertebrate fibroblast growth factor receptor (FGFR) family is an important group of proteins involved in embryonic development and the growth and proliferation of adult cells. Mutations in FGFR proteins can lead to pathologies including bone or limb defects and various forms of cancer. FGFR proteins are receptor tyrosine kinases that, upon ligand binding, dimerize and signal through the MAPK and PLCγ pathways. FGFR1 is a well characterized member of this protein family consisting of an extracellular region, a single-pass transmembrane domain, and the intracellular tyrosine kinase domain. The extracellular region contains a heparin binding domain responsible for interaction with the extracellular matrix while the intracellular domain interacts with downstream effectors after receptor dimerization to propagate signals (1). FGFR1 exists in many alternatively spliced isoforms including a soluble, secreted isoform lacking the transmembrane and kinase domains. While...