Chromatin-bound mitogen-activated protein kinases transmit dynamic signals in transcription complexes in beta-cells.
MAPK pathways regulate transcription through phosphorylation of transcription factors and other DNA-binding proteins. In pancreatic beta-cells, ERK1/2 are required for transcription of the insulin gene and several other genes in response to glucose. We show that binding of glucose-sensitive transcription activators and repressors to the insulin gene promoter depends on ERK1/2 activity. We also find that glucose and NGF stimulate the binding of ERK1/2 to the insulin gene and other promoters. An ERK1/2 cascade module, including MEK1/2 and Rsk, are found in complexes bound to these promoters. These findings imply that MAPK-containing signaling complexes are positioned on sensitive promoters with their protein substrates to modulate transcription in situ in response to incoming signals.
Lawrence
Michael C
MC
Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.
McGlynn
Kathleen
K
Shao
Chunli
C
Duan
Lingling
L
Naziruddin
Bashoo
B
Levy
Marlon F
MF
Cobb
Melanie H
MH