GSBS Student Publications

Title

Transcriptional autoregulation of the bone related CBFA1/RUNX2 gene

GSBS Program

Biochemistry & Molecular Pharmacology

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Cell Biology

Date

7-27-2000

Document Type

Article

Medical Subject Headings

5' Untranslated Regions; Animals; Base Sequence; Bone and Bones; Cell Line; Cloning, Molecular; Consensus Sequence; Core Binding Factor Alpha 1 Subunit; DNA, Complementary; Down-Regulation; Gene Expression Regulation; Humans; Mice; Molecular Sequence Data; *Neoplasm Proteins; Promoter Regions (Genetics); Rats; Transcription Factors; Transcription, Genetic; Transfection

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The runt related transcription factor CBFA1 (AML3/PEBP2alphaA/RUNX2) regulates expression of several bone- and cartilage-related genes and is required for bone formation in vivo. The gene regulatory mechanisms that control activation and repression of CBFA1 gene transcription during osteoblast differentiation and skeletal development are essential for proper execution of the osteogenic program. We have therefore defined functional contributions of 5' regulatory sequences conserved in rat, mouse and human CBFA1 genes to transcription. Deletion analysis reveals that 0.6 kB of the bone-related rat or mouse CBFA1 promoter (P1, MASNS protein isoform) is sufficient to confer transcriptional activation, and that there are multiple promoter domains which positively and negatively regulate transcription. Progressive deletion of promoter segments between nt -351 and -92 causes a striking 30- to 100-fold combined decrease in promoter activity. Additionally, 5' UTR sequences repress reporter gene transcription 2- to 3-fold. Our data demonstrate that CBFA1 is a principal DNA binding protein interacting with the 5' region of the CBFA1 gene in osseous cells, that there are at least three CBFA1 recognition motifs in the rat CBFA1 promoter, and that there are three tandemly repeated CBFA1 sites within the 5' UTR. We find that forced expression of CBFA1 protein downregulates CBFA1 promoter activity and that a single CBFA1 site is sufficient for transcriptional autosuppression. Thus, our data indicate that the CBFA1 gene is autoregulated in part by negative feedback on its own promoter to stringently control CBFA1 gene expression and function during bone formation.

Rights and Permissions

Citation: J Cell Physiol. 2000 Sep;184(3):341-50. Link to article on publisher's site

Related Resources

Link to article in PubMed

Journal Title

Journal of cellular physiology

PubMed ID

10911365