Adhesion regulates MAP kinase/ternary complex factor exchange to control a proliferative transcriptional switch

TY - JOUR

T1 - Adhesion regulates MAP kinase/ternary complex factor exchange to control a proliferative transcriptional switch

AU - Wozniak, Michele A

AU - Cheng, Catherine Q

AU - Shen, Colette J

AU - Gao, Lin

AU - Olarerin-George, Anthony O

AU - Won, Kyoung-Jae

AU - Hogenesch, John B

AU - Chen, Christopher S

N1 - Copyright © 2012 Elsevier Ltd. All rights reserved.

PY - 2012/11/6

Y1 - 2012/11/6

N2 - BACKGROUND: The ternary complex factors (TCFs; Elk1, Net, and Sap-1) are growth factor-responsive transcription cofactors of serum response factor (SRF) and are activated by MAP kinase (MAPK) phosphorylation to regulate immediate early gene transcription. Although cell adhesion also can regulate immediate early genes and proliferation, the mechanism for this effect has remained unexplored.RESULTS: Restricting adhesion and spreading of G(0)-synchronized cells on substrates with decreasing size of micropatterned islands of fibronectin suppressed serum-induced immediate early gene expression and S phase entry. Knockdown of Sap-1 decreased expression of the immediate early genes egr1 and fos and subsequent proliferation normally present with high adhesion, whereas knockdown of Net rescued egr1 and fos expression and proliferation normally suppressed by low adhesion. Chromatin immunoprecipitation studies showed increased occupancy of egr1 and fos promoters by Sap-1 with high adhesion, whereas low adhesion increased Net occupancy. This switch in TCF promoter binding was regulated by an adhesion-mediated switch in MAPK activity. Increasing adhesion enhanced serum-induced JNK activity while suppressing p38 activity, leading to increased Sap-1 phosphorylation and Net dephosphorylation, and switching Net with Sap-1 at egr1 and fos promoters to support proliferation. Microarray studies confirmed this switch in TCF regulation of proliferative genes and uncovered novel gene targets and functions coregulated by Sap-1 and Net.CONCLUSIONS: These data demonstrate a key role for the TCFs in adhesion-induced transcription and proliferation and reveal a novel MAPK/TCF transcriptional switch that controls this process.

AB - BACKGROUND: The ternary complex factors (TCFs; Elk1, Net, and Sap-1) are growth factor-responsive transcription cofactors of serum response factor (SRF) and are activated by MAP kinase (MAPK) phosphorylation to regulate immediate early gene transcription. Although cell adhesion also can regulate immediate early genes and proliferation, the mechanism for this effect has remained unexplored.RESULTS: Restricting adhesion and spreading of G(0)-synchronized cells on substrates with decreasing size of micropatterned islands of fibronectin suppressed serum-induced immediate early gene expression and S phase entry. Knockdown of Sap-1 decreased expression of the immediate early genes egr1 and fos and subsequent proliferation normally present with high adhesion, whereas knockdown of Net rescued egr1 and fos expression and proliferation normally suppressed by low adhesion. Chromatin immunoprecipitation studies showed increased occupancy of egr1 and fos promoters by Sap-1 with high adhesion, whereas low adhesion increased Net occupancy. This switch in TCF promoter binding was regulated by an adhesion-mediated switch in MAPK activity. Increasing adhesion enhanced serum-induced JNK activity while suppressing p38 activity, leading to increased Sap-1 phosphorylation and Net dephosphorylation, and switching Net with Sap-1 at egr1 and fos promoters to support proliferation. Microarray studies confirmed this switch in TCF regulation of proliferative genes and uncovered novel gene targets and functions coregulated by Sap-1 and Net.CONCLUSIONS: These data demonstrate a key role for the TCFs in adhesion-induced transcription and proliferation and reveal a novel MAPK/TCF transcriptional switch that controls this process.

KW - 3T3 Cells

KW - Adaptor Proteins, Vesicular Transport/genetics

KW - Animals

KW - Cell Adhesion/physiology

KW - Cell Line

KW - Cell Proliferation

KW - Early Growth Response Protein 1/genetics

KW - JNK Mitogen-Activated Protein Kinases/metabolism

KW - Mice

KW - Mitogen-Activated Protein Kinases/metabolism

KW - Phosphorylation

KW - Promoter Regions, Genetic

KW - Proto-Oncogene Proteins c-ets/genetics

KW - Proto-Oncogene Proteins c-fos/genetics

KW - Serum Response Factor/metabolism

KW - Sodium Channels/genetics

KW - Ternary Complex Factors/metabolism

KW - Transcription, Genetic

KW - p38 Mitogen-Activated Protein Kinases/metabolism

U2 - 10.1016/j.cub.2012.08.050

DO - 10.1016/j.cub.2012.08.050

M3 - Journal article

C2 - 23063436

SN - 0960-9822

VL - 22

SP - 2017

EP - 2026

JO - Current biology : CB

JF - Current biology : CB

IS - 21

ER -