SAF-B protein couples transcription and pre-mRNA splicing to SAR/MAR elements

Nucleic Acids Res. 1998 Aug 1;26(15):3542-9. doi: 10.1093/nar/26.15.3542.

Abstract

Interphase chromatin is arranged into topologically separated domains comprising gene expression and replication units through genomic sequence elements, so-called MAR or SAR regions (for matrix- or scaffold-associating regions). S/MAR regions are located near the boundaries of actively transcribed genes and were shown to influence their activity. We show that scaffold attachment factor B (SAF-B), which specifically binds to S/MAR regions, interacts with RNA polymerase II (RNA pol II) and a subset of serine-/arginine-rich RNA processing factors (SR proteins). SAF-B localized to the nucleus in a speckled pattern that coincided with the distribution of the SR protein SC35. Furthermore, we show that overexpressed SAF-B induced an increase of the 10S splice product using an E1A reporter gene and repressed the activity of an S/MAR flanked CAT reporter gene construct in vivo . This indicates an association of SAF-B with SR proteins and components of the transcription machinery. Our results describe the coupling of a chromatin organizing S/MAR element with transcription and pre-mRNA processing components and we propose that SAF-B serves as a molecular base to assemble a 'transcriptosome complex' in the vicinity of actively transcribed genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Animals
  • Binding Sites
  • Cell Line
  • Cell Nucleus / metabolism
  • Chloramphenicol O-Acetyltransferase / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Genes, Reporter
  • Humans
  • Matrix Attachment Region Binding Proteins*
  • Mice
  • Nuclear Matrix-Associated Proteins*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Nucleic Acid Hybridization
  • Phosphoproteins / metabolism
  • Phosphorylation
  • RNA Polymerase II / metabolism
  • RNA Precursors*
  • RNA Splicing*
  • RNA-Binding Proteins
  • Rats
  • Receptors, Estrogen*
  • Saccharomyces cerevisiae
  • Serine-Arginine Splicing Factors
  • Transcription, Genetic*

Substances

  • DNA-Binding Proteins
  • Matrix Attachment Region Binding Proteins
  • Nuclear Matrix-Associated Proteins
  • Nuclear Proteins
  • Phosphoproteins
  • RNA Precursors
  • RNA-Binding Proteins
  • Receptors, Estrogen
  • SAFB protein, human
  • Safb protein, rat
  • Serine-Arginine Splicing Factors
  • Chloramphenicol O-Acetyltransferase
  • RNA Polymerase II

Associated data

  • GENBANK/AF056324