title: TIG3: a regulator of type I transglutaminase activity in epidermis.
abstract: Keratinocytes undergo a process of terminal cell differentiation that results in the construction of a multilayered epithelium designed to produce a structure that functions to protect the body from dehydration, abrasion and infection. These protective properties are due to the production of a crosslinked layer of protein called the cornified envelope. Type I transglutaminase (TG1), an enzyme that catalyzes the formation of epsilon-(gamma-glutamyl)lysine bonds, is the key protein responsible for generation of the crosslinks. The mechanisms that lead to activation of transglutaminase during terminal differentiation are not well understood. We have identified a protein that interacts with TG1 and regulates its activity. This protein, tazarotene-induced gene 3 (TIG3), is expressed in the differentiated layers of the epidermis and its expression is associated with transglutaminase activation and cornified envelope formation. We describe a novel mechanism whereby TIG3 regulates TG1 activity.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 N. Greene Street, Baltimore, MD 21201, USA. reckert@umaryland.edu
authors.forename: Richard L
authors.initials: RL
authors.lastname: Eckert
authors.forename: Michael T
authors.initials: MT
authors.lastname: Sturniolo
authors.forename: Ralph
authors.initials: R
authors.lastname: Jans
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Kraft
authors.forename: Haibing
authors.initials: H
authors.lastname: Jiang
authors.forename: Ellen A
authors.initials: EA
authors.lastname: Rorke
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D000078404:Epidermal Cells; D004817:Epidermis / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000096:biosynthesis / Q000378:metabolism*; D011503:Transglutaminases / Q000378:metabolism*
chemical_list: C437968:PLAAT4 protein, human; D018168:Receptors, Retinoic Acid; D011503:Transglutaminases; C105804:transglutaminase 1