Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2007 Nov 2;282(44):32021-31. Epub 2007 Sep 5.

MLH1- and ATM-dependent MAPK signaling is activated through c-Abl in response to the alkylator N-methyl-N'-nitro-N'-nitrosoguanidine.

Author information

  • 1Department of Biochemistry and Molecular Biology and the University of Florida Shands Cancer Center, University of Florida College of Medicine, Gainesville, Florida 32610, USA.

Abstract

N-Methyl-N'-nitro-N'-nitrosoguanidine (MNNG) is a DNA-methylating agent, and deficiency in mismatch repair (MMR) results in lack of sensitivity to this genotoxin (termed alkylation tolerance). A number of DNA damage response pathways are activated in a MMR-dependent manner following MNNG, and several also require ATM kinase activity. Here we show that activation of the transcription factor c-Jun is dependent upon both the MMR component MLH1 and ATM, but not ATR, in response to MNNG. In addition to c-Jun, the upstream MAPKs JNK and MKK4 are also activated in a MLH1- and ATM-dependent manner. We document that c-Jun activation is dependent on the MAPK kinase kinase MEKK1. Additionally, the tyrosine kinase c-Abl is required to activate this signaling cascade and forms a complex with MEKK1 and MLH1. This study indicates that an arm of DNA damage-activated MAPK signaling is activated in an MLH1- and ATM-dependent manner in response to MNNG and perhaps suggests that dysregulation of this signaling is responsible, in part, for alkylation tolerance.

PMID:
17804421
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk