Transcriptional Analysis of the 5′-Noncoding Region of the Human Involucrin Gene

doi:10.1074/jbc.271.1.512

Transcriptional Analysis of the 5′-Noncoding Region of the Human Involucrin Gene (*)

From the Departamento de Genetica y Biologia Molecular, Centro de Investigacion y Estudios Avanzados del Instituto Politecnico Nacional, AP 14-740, Mexico 07000 Distrito Federal, Mexico and the
Laboratory of Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892-4255

^§§Sistema Nacional de Investigadores National Researcher Candidate Fellowship recipient. To whom correspondence should be addressed. Tel.: 301-496-6442; Fax: 301-496-3238; luism{at}helix.nih.gov.

Abstract

Human involucrin whose gene transcription is directed by a 2456-nucleotide (nt) 5′-noncoding region is a structural component of the epithelial cornified layer. Transient transfection assays demonstrated that this region is transcriptionally active in multiplying keratinocytes and is enhanced by 2 mM CaCl treatment. Calcium-independent transcriptional activity and the interaction with the AP-1 transcriptional factor was located on the proximal part (nt −159 to −1) of the 5′-noncoding region. However, CaCl responsiveness was mapped to a distal 1185-nt fragment (nt −2456 to −1272). Moreover, this fragment potentiated the Herpes simplex thymidine kinase promoter in normal keratinocytes and is responsive to calcium treatment in a cell type-specific manner. Interestingly, the absence of a 491-nt fragment located between the two enhancer domains (nt −651 to −160) resulted in transcriptional activation in multiplying keratinocytes. This fragment interacts with AP-1 and the YY1 transcriptional silencer. It is concluded that human involucrin 5′-noncoding region contains at least three regulatory domains, a distal CaCl-responsive enhancer, a putative transcriptional silencer (that interacts with AP-1 and YY1), and a proximal enhancer/promoter (that interacts with AP-1). Thus, this study demonstrates the presence of particular transcriptional factors can potentially regulate the human involucrin expression.

Footnotes

↵^§ Sistema Nacional de Investigadores National Researcher Candidate Fellowship recipient.
↵^¶ Supported by Consejo Nacional de Ciencia y Tecnologia M.Sc. program.
↵* *Aaron Saenz Fellowship recipient.
↵* This work was supported by Consejo Nacional de Ciencia y Tecnologia Grant N9107-0346. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

TPA

12-O-tetradecanoylphorbol-13-acetate

nt

nucleotide(s)

CAT

chloramphenicol acetyltransferase

HP1, HP2, HP3 and HP4

proximal footprints

H1, H2, H3, and H4

distal footprints

SV40

simian virus 40

TK

thymidine kinase.
- Received September 20, 1995.