title: Expression of an immediate early gene, IEX-1, in human tissues.
abstract: IEX-1 is an immediate early gene that is induced by ionizing radiation, ultraviolet radiation, and a variety of growth factors. It plays an important role in the regulation of cellular growth. Earlier, we performed studies on the distribution of IEX-1 messenger RNA in different tissues and on the subcellular localization of IEX-1 protein. No reports, however, have appeared concerning the distribution of IEX-1 protein in a variety of human tissues. We raised a polyclonal antibody against a synthetic IEX-1 peptide (amino acids 51-75) and used the antibody to study the distribution of the protein in human tissues. We demonstrate that IEX-1 is strongly expressed in epithelia of the skin, trachea, gastrointestinal, and genitourinary systems, as well as in the pancreas and breast. Endothelial cells within the vasculature of most tissue/organs also strongly express IEX-1. Liver, lung, lymph nodes, and placenta stain weakly. No IEX-1 epitopes were detected in the thymus, testes, ovary, myocardium, skeletal muscle, or spleen. We conclude that IEX-1 is widely expressed in epithelial and endocrine tissues, as well as in vascular endothelium.
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Feldmann
authors.forename: M R
authors.initials: MR
authors.lastname: Pittelkow
authors.forename: P C
authors.initials: PC
authors.lastname: Roche
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: J P
authors.initials: JP
authors.lastname: Grande
mesh_terms: D000595:Amino Acid Sequence; D051017:Apoptosis Regulatory Proteins; D004064:Digestive System / Q000378:metabolism; D005260:Female; D006801:Humans; D017874:Immediate-Early Proteins / Q000096:biosynthesis*; D008221:Lymphoid Tissue / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D009363:Neoplasm Proteins; D009420:Nervous System / Q000378:metabolism; D011467:Prostate / Q000378:metabolism; D012137:Respiratory System / Q000378:metabolism; D012867:Skin / Q000378:metabolism / Q000473:pathology; D014018:Tissue Distribution; D014566:Urogenital System / Q000378:metabolism; D014599:Uterus / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; C099815:IER3 protein, human; D017874:Immediate-Early Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins