Antibodies

This gene encodes the major 3' to 5' DNA exonuclease in human cells. The protein is a non-processive exonuclease that appears to provide proofreading for checkpoint signaling after DNA damage in response to oxidative stress and apoptosis. It is ubiquitously expressed. Trex1 binds to single-stranded DNA coated with replication protein A found at sites of DNA damage, and recruits the ataxia telangiectasia and Rad3 related protein (ATR) checkpoint kinase.

Peroxisome proliferators are non-genotoxic carcinogens which are purported to exert their effect on cells by interacting with members of the nuclear hormone receptor superfamily known as peroxisome proliferator activated receptors (PPARs). There are four of these nuclear hormone receptors known to date, and they are ligand-dependent intracellular proteins that stimulate downstream gene transcription of genes such as acyl coenzyme A oxidase and cytochrome P450 (CYP450). Activation occurs through direct binding to specific DNA response elements following activation by an appropriate ligand.

Albumin is a soluble and globular monomeric protein encoded by chromosome 4 that comprises about half of the protein found in blood serum. It functions as a carrier protein for steroids, fatty acids, and thyroid hormones as well as stabilizing extracellular fluid volume. Gene mutations result in various anomalous proteins. Albumin is synthesized in the liver as a preproalbumin with an N-terminal peptide that is removed before the nascent protein is released from the rough endoplasmic reticulum (ER).

SHARP1 encodes a transcription repressor factor that belongs to the Hairy/Enhancer of the Split subfamily of basic helix-loop-helix factors (bHLH). Sequence alignment shows that SHARP1 is only distantly related to these proteins with a 37-42% sequence identity within its bHLH domain. Unlike most other bHLH proteins, SHARP-1 is not expressed in neuronal progenitor cells or early differentiating neurons but is instead restricted to neuronal subset within the postnatal central nervous system (CNS).

The thymidine synthetic nucleoside analogue bromodeoxyuridine (BrdU) has a long, colorful history of repeated use in molecular and cytokinetic studies, as detailed in reviews by Vanderlaan and Dolbeare (1,2).  Because BrDU is only incorporated into newly synthesized DNA in actively replicating S-phase cells, it allows for accurate and comprehensive quantitation of the pattern, rate, and progression of cell proliferation.

CD73 is a 70kD glycosyl-phosphatidylinositol (GPI)-anchored cell surface molecule that belongs to the 5'-nucleosidase family. It hydrolyzes extracellular nucleotides into membrane permeable nucleosides and is found as both a membrane-bound and soluble molecule. Because it is abundantly expressed on vascular endothelium and some lymphocyte subpopulations, CD73 is a useful lymphocyte differentiation marker. Like many other GPI-anchored molecules, it transmits T-cell activation signals upon ligand engagement.

CD33 is a transmembrane protein that belongs to the sialic acid-binding immunoglobulin-like lectin (siglec) family. These are immunoreceptor tyrosine-based inhibitory motif (ITIM)-containing molecules capable of recruiting the tyrosine phosphatases SHP-1 and SHP-2 to signal assemblies. ITIMs are also used for the ubiquitin-mediated removal of the receptor from cell surfaces. CD33 is expressed on cells of myelomonocytic lineage.

CD90 is a 25-35kD glycosylphosphatidylinositol (GPI)-linked glycoprotein receptor of the immunoglobulin (Ig) superfamily. It is found on murine T-cells, thymocytes, neuronal cells, granulocytic lineage-derived cells, hematopoietic stem cells, fibroblasts, neurons, and Kupffer's cells. CD90 is often used as a marker for a variety of stem cells and mature neuronal axon processes.  CD90 appears to play a role in cell-cell and cell-matrix interactions and adhesion during synaptogenesis, nerve regeneration, apoptosis and necrosis, inflammation, fibrosis, and metastasis.

GLUT4 is an insulin-sensitive glucose transporter that facilitates insulin-stimulated glucose uptake in adipose tissue, skeletal muscle, and cardiac tissues that specifically express this protein. It is a twelve transmembrane domain multi-pass protein found only in the endosome system and perinuclear cytoplasm. Upon insulin stimulation, GLUT4 translocates to the cell surface. Because of its role in glucose homeostasis, GLUT4 is the key regulator of obesity and obesity-related disease.

CD16 is a lymphocyte Fc gamma type III low-affinity receptor for IgG and is represented by two similar genes, CD16A (Fc gamma RIII A) and CD16B (Fc gamma RIIIB). CD16A exists as a heterooligomeric polypeptide-anchored form in macrophages and NK cells. CD16B exists as a monomeric glycosylphosphatidylinositol (GPI)-anchored form in neutrophils. CD16 binds IgG in the form of immune complexes or free antibody. It exhibits preferential binding to IgG1 and IgG3 isotypes, with minimal binding of IgG2 and IgG4.