title: Immunolocalization of protein 4.1B in the rat digestive system.
abstract: Protein 4.1 family proteins are thought to interact with membrane proteins and also membrane skeletons. In this study, immunohistochemical studies by light and electron microscopy were performed with a specific antibody against protein 4.1B. Specific protein 4.1B immunolabeling was observed in simple columnar epithelium in the adult rat large intestine, small intestine and stomach. Protein 4.1B immunolabeling was localized along the membranes facing the adjacent cells (lateral portion) and also facing the extracellular matrix (basal portion). Moreover, a spatial protein 4.1B expression gradient was observed along the crypt-villus axis of the rat small and large intestinal epithelium: strong protein 4.1B expression was present within the villus, with the crypt showing barely any detectable protein 4.1B. The expression of protein 4.1B was not detected in the stratified squamous epithelium in the forestomach or the esophagus. By immunoelectron microscopy, the immunolabeling of the cells was observed to be restricted to the cytoplasmic side just beneath the plasma membrane, including the membranes adjacent to the next cells, except for the tight junctions. We conclude that the protein 4.1B expression pattern is related to the maturation of simple columnar epithelium in the rat digestive system, probably by the effect of adhesion.
authors.affiliation: Department of Anatomy, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Tamaho, Japan. nobuot@yamanashi.ac.jp
authors.forename: Nobuo
authors.initials: N
authors.lastname: Terada
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Ohno
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamakawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Baba
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Fujii
authors.forename: Osamu
authors.initials: O
authors.lastname: Ohara
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ohno
mesh_terms: D000818:Animals; D003598:Cytoskeletal Proteins / Q000096:biosynthesis*; D004064:Digestive System / Q000378:metabolism* / Q000648:ultrastructure; D004848:Epithelium / Q000378:metabolism* / Q000648:ultrastructure; D005786:Gene Expression Regulation / Q000502:physiology*; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000096:biosynthesis*; D016253:Microscopy, Immunoelectron; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; C028841:erythrocyte membrane band 4.1 protein