Abstract
The E3 ubiquitin ligase IMP (impedes mitogenic signal propagation) was isolated as a novel Ras effector that negatively regulates ERK1/2 activation. Current evidence suggests that IMP limits the functional assembly of Raf/MEK complexes by inactivation of the KSR1 adaptor/scaffold protein. Interaction with Ras-GTP stimulates IMP autoubiquitination to relieve limitations on KSR function. The elevated sensitivity of IMP-depleted cells to ERK1/2 pathway activation suggests IMP acts as a signal threshold regulator by imposing reversible restrictions on the assembly of functional Raf/MEK/ERK kinase modules. These observations challenge commonly held concepts of signal transmission by Ras to the MAPK pathway and provide evidence for the role of amplitude modulation in tuning cellular responses to ERK1/2 pathway engagement. Here we describe details of the methods, including RNA interference, ubiquitin ligase assays, and protein complex analysis, that can be used to display the Ras-sensitive contribution of IMP to KSR-dependent modulation of the Raf/MEK/ERK pathway.
Original language | English (US) |
---|---|
Pages (from-to) | 237-247 |
Number of pages | 11 |
Journal | Methods in Enzymology |
Volume | 407 |
DOIs | |
State | Published - 2005 |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Ras-Sensitive IMP Modulation of the Raf/MEK/ERK Cascade Through KSR1. / Matheny, Sharon A.; White, Michael A.
In: Methods in Enzymology, Vol. 407, 2005, p. 237-247.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ras-Sensitive IMP Modulation of the Raf/MEK/ERK Cascade Through KSR1
AU - Matheny, Sharon A.
AU - White, Michael A.
PY - 2005
Y1 - 2005
N2 - The E3 ubiquitin ligase IMP (impedes mitogenic signal propagation) was isolated as a novel Ras effector that negatively regulates ERK1/2 activation. Current evidence suggests that IMP limits the functional assembly of Raf/MEK complexes by inactivation of the KSR1 adaptor/scaffold protein. Interaction with Ras-GTP stimulates IMP autoubiquitination to relieve limitations on KSR function. The elevated sensitivity of IMP-depleted cells to ERK1/2 pathway activation suggests IMP acts as a signal threshold regulator by imposing reversible restrictions on the assembly of functional Raf/MEK/ERK kinase modules. These observations challenge commonly held concepts of signal transmission by Ras to the MAPK pathway and provide evidence for the role of amplitude modulation in tuning cellular responses to ERK1/2 pathway engagement. Here we describe details of the methods, including RNA interference, ubiquitin ligase assays, and protein complex analysis, that can be used to display the Ras-sensitive contribution of IMP to KSR-dependent modulation of the Raf/MEK/ERK pathway.
AB - The E3 ubiquitin ligase IMP (impedes mitogenic signal propagation) was isolated as a novel Ras effector that negatively regulates ERK1/2 activation. Current evidence suggests that IMP limits the functional assembly of Raf/MEK complexes by inactivation of the KSR1 adaptor/scaffold protein. Interaction with Ras-GTP stimulates IMP autoubiquitination to relieve limitations on KSR function. The elevated sensitivity of IMP-depleted cells to ERK1/2 pathway activation suggests IMP acts as a signal threshold regulator by imposing reversible restrictions on the assembly of functional Raf/MEK/ERK kinase modules. These observations challenge commonly held concepts of signal transmission by Ras to the MAPK pathway and provide evidence for the role of amplitude modulation in tuning cellular responses to ERK1/2 pathway engagement. Here we describe details of the methods, including RNA interference, ubiquitin ligase assays, and protein complex analysis, that can be used to display the Ras-sensitive contribution of IMP to KSR-dependent modulation of the Raf/MEK/ERK pathway.
UR - http://www.scopus.com/inward/record.url?scp=33744505581&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33744505581&partnerID=8YFLogxK
U2 - 10.1016/S0076-6879(05)07020-5
DO - 10.1016/S0076-6879(05)07020-5
M3 - Article
C2 - 16757328
AN - SCOPUS:33744505581
VL - 407
SP - 237
EP - 247
JO - Methods in Enzymology
JF - Methods in Enzymology
SN - 0076-6879
ER -