Transcriptional activation by MEIS1A in response to protein kinase A signaling requires the transducers of regulated CREB family of CREB co-activators

J Biol Chem. 2009 Jul 10;284(28):18904-12. doi: 10.1074/jbc.M109.005090. Epub 2009 May 27.

Abstract

The transcription factor encoded by the murine ecotropic integration site 1 gene (MEIS1) is a partner of HOX and PBX proteins. It has been implicated in embryonic patterning and leukemia, and causally linked to restless legs syndrome. The MEIS1A C terminus harbors a transcriptional activation domain that is stimulated by protein kinase A (PKA) in a manner dependent on the co-activator of cAMP response element-binding protein (CREB), CREB-binding protein (CBP). We explored the involvement of another mediator of PKA-inducible transcription, namely the CREB co-activators transducers of regulated CREB activity (TORCs). Overexpression of TORC1 or TORC2 bypassed PKA for activation by MEIS1A. Co-immunoprecipitation experiments demonstrated a physical interaction between MEIS1 and TORC2 that is dependent on the MEIS1A C terminus, whereas chromatin immunoprecipitation revealed PKA-inducible recruitment of MEIS1, PBX1, and TORC2 on the MEIS1 target genes Hoxb2 and Meis1. The MEIS1 interaction domain on TORC1 was mapped to the N-terminal coiled-coil region, and TORC1 mutants lacking this domain attenuated the response to PKA on a natural MEIS1A target enhancer. Thus, TORCs physically cooperate with MEIS1 to achieve PKA-inducible transactivation through the MEIS1A C terminus, suggesting a concerted action in developmental and oncogenic processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Chromatin Immunoprecipitation
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Cyclic AMP-Dependent Protein Kinases / metabolism*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism
  • Homeodomain Proteins / metabolism*
  • Humans
  • Mice
  • Models, Biological
  • Myeloid Ecotropic Viral Integration Site 1 Protein
  • Neoplasm Proteins / metabolism*
  • Pre-B-Cell Leukemia Transcription Factor 1
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / metabolism
  • Signal Transduction
  • Transcription Factors / metabolism
  • Transcriptional Activation*

Substances

  • CRTC1 protein, human
  • CRTC2 protein, human
  • Cyclic AMP Response Element-Binding Protein
  • DNA-Binding Proteins
  • Homeodomain Proteins
  • MEIS1 protein, human
  • Meis1 protein, mouse
  • Myeloid Ecotropic Viral Integration Site 1 Protein
  • Neoplasm Proteins
  • Pre-B-Cell Leukemia Transcription Factor 1
  • Proto-Oncogene Proteins
  • Transcription Factors
  • PBX1 protein, human
  • Cyclic AMP-Dependent Protein Kinases