GSBS Student Publications

Title

The tissue-specific nuclear matrix protein, NMP-2, is a member of the AML/CBF/PEBP2/runt domain transcription factor family: interactions with the osteocalcin gene promoter

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Cell Biology

Date

10-10-1995

Document Type

Article

Medical Subject Headings

Animals; Base Sequence; Consensus Sequence; DNA-Binding Proteins; Gene Expression Regulation; Molecular Sequence Data; Nuclear Matrix; Nuclear Proteins; Oligodeoxyribonucleotides; Osteocalcin; Promoter Regions (Genetics); Rats; Transcription Factors; Tumor Cells, Cultured

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The nuclear matrix protein, NMP-2, was originally identified as an osteoblast-specific DNA-binding complex localized exclusively to the nuclear matrix. NMP-2 was shown to recognize two binding sites, site A (nt-605 to -599) and site B (nt -441 to -435), in the rat bone-specific osteocalcin gene promoter. This study shows that the NMP-2 binding sites A and B as well as a third NMP-2 binding site (nt -135 to -130) constitute a consensus sequence, ATGCTGGT, and represent an AML-1 recognition motif. AML-1 is a member of the AML transcription factor family which is associated with acute myelogenous leukemia and binds to the sequence TGCTGGT via its DNA-binding runt domain. Electrophoretic mobility shift assays reveal that a component of NMP-2 is a member of the AML/PEBP2/runt domain transcription factor family based on cross-competition with AML-1 consensus oligonucleotide. Limited immunoreactivity of NMP-2 with a polyclonal N-terminal AML-1 antibody and inability of the AML-1 partner protein CBF-beta to form complexes with NMP-2 indicate that NMP-2 is not identical to AML-1 but represents a variant AML/PEBP2/runt domain protein. Western and Northern blots reveal the presence of multiple AML-related proteins and AML-1 transcripts in several osseous cell lines. Furthermore, our results indicate that AML family members may selectively partition between nuclear matrix and nonmatrix compartments. Because proteins that contain a runt domain are implicated in tissue-specific transcriptional regulation, our results support the concept that the nuclear matrix mediates osteoblast-specific expression of the osteocalcin gene.

Rights and Permissions

Citation: Biochemistry. 1995 Oct 10;34(40):13125-32.

Related Resources

Link to article in PubMed

Journal Title

Biochemistry

PubMed ID

7548073