Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Sequence-Selective Covalent CaaX-Box Receptors Prevent Farnesylation of Oncogenic Ras Proteins and Impact MAPK/PI3 K Signaling.

ABSTRACT: Oncogenic Ras proteins are implicated in the most common life-threatening cancers. Despite intense research over the past two decades, the progress towards small-molecule inhibitors has been limited. One reason for this failure is that Ras proteins interact with their effectors only via protein-protein interactions, which are notoriously difficult to address with small organic molecules. Herein we describe an alternative strategy, which prevents farnesylation and subsequent membrane insertion, a prerequisite for the activation of Ras proteins. Our approach is based on sequence-selective supramolecular receptors which bind to the C-terminal farnesyl transferase recognition unit of Ras and Rheb proteins and covalently modify the essential cysteine in the so-called CaaX-box.

SUBMITTER: Franz M

PROVIDER: S-EPMC8453727 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Sequence-Selective Covalent CaaX-Box Receptors Prevent Farnesylation of Oncogenic Ras Proteins and Impact MAPK/PI3 K Signaling.

Franz Matthias M Mörchen Britta B Degenhart Carsten C Gülden Daniel D Shkura Oleksandr O Wolters Dirk D Koch Uwe U Klebl Bert B Stoll Raphael R Helfrich Iris I Scherkenbeck Jürgen J

ChemMedChem 20210519 16

Oncogenic Ras proteins are implicated in the most common life-threatening cancers. Despite intense research over the past two decades, the progress towards small-molecule inhibitors has been limited. One reason for this failure is that Ras proteins interact with their effectors only via protein-protein interactions, which are notoriously difficult to address with small organic molecules. Herein we describe an alternative strategy, which prevents farnesylation and subsequent membrane insertion, a ...[more]

PMID: 33899342

Similar Datasets

Oncogenic ETS proteins mimic activated RAS/MAPK signaling in prostate cells.

Project description:The aberrant expression of an oncogenic ETS transcription factor is implicated in the progression of the majority of prostate cancers, 40% of melanomas, and most cases of gastrointestinal stromal tumor and Ewing's sarcoma. Chromosomal rearrangements in prostate cancer result in overexpression of any one of four ETS transcription factors. How these four oncogenic ETS genes differ from the numerous other ETS genes expressed in normal prostate and contribute to tumor progression is not understood. We report that these oncogenic ETS proteins, but not other ETS factors, enhance prostate cell migration. Genome-wide binding analysis matched this specific biological function to occupancy of a unique set of genomic sites highlighted by the presence of ETS- and AP-1-binding sequences. ETS/AP-1-binding sequences are prototypical RAS-responsive elements, but oncogenic ETS proteins activated a RAS/MAPK transcriptional program in the absence of MAPK activation. Thus, overexpression of oncogenic ETS proteins can replace RAS/MAPK pathway activation in prostate cells. The genomic description of this ETS/AP-1-regulated, RAS-responsive, gene expression program provides a resource for understanding the role of these ETS factors in both an oncogenic setting and the developmental processes where these genes normally function.

| S-EPMC3205585 | biostudies-literature

Therapeutic targeting of oncogenic K-Ras by a covalent catalytic site inhibitor.

Project description:We report the synthesis of a GDP analogue, SML-8-73-1, and a prodrug derivative, SML-10-70-1, which are selective, direct-acting covalent inhibitors of the K-Ras G12C mutant relative to wild-type Ras. Biochemical and biophysical measurements suggest that modification of K-Ras with SML-8-73-1 renders the protein in an inactive state. These first-in-class covalent K-Ras inhibitors demonstrate that irreversible targeting of the K-Ras guanine-nucleotide binding site is potentially a viable therapeutic strategy for inhibition of Ras signaling.

| S-EPMC3914205 | biostudies-literature

Oncogenic mutant RAS signaling activity is rescaled by the ERK/MAPK pathway.

Project description:Activating mutations in RAS are present in ~ 30% of human tumors, and the resulting aberrations in ERK/MAPK signaling play a central role in oncogenesis. However, the form of these signaling changes is uncertain, with activating RAS mutants linked to both increased and decreased ERK activation in vivo. Rationally targeting the kinase activity of this pathway requires clarification of the quantitative effects of RAS mutations. Here, we use live-cell imaging in cells expressing only one RAS isoform to quantify ERK activity with a new level of accuracy. We find that despite large differences in their biochemical activity, mutant KRAS isoforms within cells have similar ranges of ERK output. We identify roles for pathway-level effects, including variation in feedback strength and feedforward modulation of phosphatase activity, that act to rescale pathway sensitivity, ultimately resisting changes in the dynamic range of ERK activity while preserving responsiveness to growth factor stimuli. Our results reconcile seemingly inconsistent reports within the literature and imply that the signaling changes induced by RAS mutations early in oncogenesis are subtle.

| S-EPMC7569415 | biostudies-literature

Hyperactive RAS/PI3-K/MAPK Signaling Cascade in Migration and Adhesion of Nf1 Haploinsufficient Mesenchymal Stem/Progenitor Cells.

Project description:Neurofibromatosis type 1 (NF1) is an autosomal dominant disease caused by mutations in the NF1 tumor suppressor gene, which affect approximately 1 out of 3000 individuals. Patients with NF1 suffer from a range of malignant and nonmalignant manifestations such as plexiform neurofibromas and skeletal abnormalities. We previously demonstrated that Nf1 haploinsufficiency in mesenchymal stem/progenitor cells (MSPCs) results in impaired osteoblastic differentiation, which may be associated with the skeletal manifestations in NF1 patients. Here we sought to further ascertain the role of Nf1 in modulating the migration and adhesion of MSPCs of the Nf1 haploinsufficient (Nf1(+/-)) mice. Nf1(+/-) MSPCs demonstrated increased nuclear-cytoplasmic ratio, increased migration, and increased actin polymerization as compared to wild-type (WT) MSPCs. Additionally, Nf1(+/-) MSPCs were noted to have significantly enhanced cell adhesion to fibronectin with selective affinity for CH271 with an overexpression of its complimentary receptor, CD49e. Nf1(+/-) MSPCs also showed hyperactivation of phosphoinositide 3-kinase (PI3-K) and mitogen activated protein kinase (MAPK) signaling pathways when compared to WT MSPCs, which were both significantly reduced in the presence of their pharmacologic inhibitors, LY294002 and PD0325901, respectively. Collectively, our study suggests that both PI3-K and MAPK signaling pathways play a significant role in enhanced migration and adhesion of Nf1 haploinsufficient MSPCs.

| S-EPMC4490447 | biostudies-literature

Chemical inhibition of CaaX protease activity disrupts yeast Ras localization.

Project description:Proteins possessing a C-terminal CaaX motif, such as the Ras GTPases, undergo extensive post-translational modification that includes attachment of an isoprenoid lipid, proteolytic processing and carboxylmethylation. Inhibition of the enzymes involved in these processes is considered a cancer-therapeutic strategy. We previously identified nine in vitro inhibitors of the yeast CaaX protease Rce1p in a chemical library screen (Manandhar et al., 2007). Here, we demonstrate that these agents disrupt the normal plasma membrane distribution of yeast GFP-Ras reporters in a manner that pharmacologically phenocopies effects observed upon genetic loss of CaaX protease function. Consistent with Rce1p being the in vivo target of the inhibitors, we observe that compound-induced delocalization is suppressed by increasing the gene dosage of RCE1. Moreover, we observe that Rce1p biochemical activity associated with inhibitor-treated cells is inversely correlated with compound dose. Genetic loss of CaaX proteolysis results in mistargeting of GFP-Ras2p to subcellular foci that are positive for the endoplasmic reticulum marker Sec63p. Pharmacological inhibition of CaaX protease activity also delocalizes GFP-Ras2p to foci, but these foci are not as strongly positive for Sec63p. Lastly, we demonstrate that heterologously expressed human Rce1p can mediate proper targeting of yeast Ras and that its activity can also be perturbed by some of the above inhibitors. Together, these results indicate that disrupting the proteolytic modification of Ras GTPases impacts their in vivo trafficking.

| S-EPMC5871226 | biostudies-literature

KIT Suppresses BRAF<sup>V600E</sup>-Mutant Melanoma by Attenuating Oncogenic RAS/MAPK Signaling.

Project description:The receptor tyrosine kinase KIT promotes survival and migration of melanocytes during development, and excessive KIT activity hyperactivates the RAS/MAPK pathway and can drive formation of melanomas, most notably of rare melanomas that occur on volar and mucosal surfaces of the skin. The much larger fraction of melanomas that occur on sun-exposed skin is driven primarily by BRAF- or NRAS-activating mutations, but these melanomas exhibit a surprising loss of KIT expression, which raises the question of whether loss of KIT in these tumors facilitates tumorigenesis. To address this question, we introduced a kit(lf) mutation into a strain of Tg(mitfa:BRAFV600E); p53(lf) melanoma-prone zebrafish. Melanoma onset was accelerated in kit(lf); Tg(mitfa:BRAFV600E); p53(lf) fish. Tumors from kit(lf) animals were more invasive and had higher RAS/MAPK pathway activation. KIT knockdown also increased RAS/MAPK pathway activation in a BRAFV600E-mutant human melanoma cell line. We found that pathway stimulation upstream of BRAFV600E could paradoxically reduce signaling downstream of BRAFV600E, and wild-type BRAF was necessary for this effect, suggesting that its activation can dampen oncogenic BRAFV600E signaling. In vivo, expression of wild-type BRAF delayed melanoma onset, but only in a kit-dependent manner. Together, these results suggest that KIT can activate signaling through wild-type RAF proteins, thus interfering with oncogenic BRAFV600E-driven melanoma formation. Cancer Res; 77(21); 5820-30. ©2017 AACR.

| S-EPMC5679278 | biostudies-literature

Oncogenic ETS proteins replace activated Ras/MAPK signaling in prostate cells.

Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations. ChIP sequencing two transcription factors in PC3 cells, four transcription factors plus a FLAG control in RWPE-1 cells and input DNA sequencing from each cell line.

2011-10-19 | E-GEOD-29808 | biostudies-arrayexpress

Thinking outside the CaaX-box: an unusual reversible prenylation on ALDH9A1.

Project description:Protein lipidation is a post-translational modification that confers hydrophobicity on protein substrates to control their cellular localization, mediate protein trafficking, and regulate protein function. In particular, protein prenylation is a C-terminal modification on proteins bearing canonical motifs catalyzed by prenyltransferases. Prenylated proteins have been of interest due to their numerous associations with various diseases. Chemical proteomic approaches have been pursued over the last decade to define prenylated proteomes (prenylome) and probe their responses to perturbations in various cellular systems. Here, we describe the discovery of prenylation of a non-canonical prenylated protein, ALDH9A1, which lacks any apparent prenylation motif. This enzyme was initially identified through chemical proteomic profiling of prenylomes in various cell lines. Metabolic labeling with an isoprenoid probe using overexpressed ALDH9A1 revealed that this enzyme can be prenylated inside cells but does not respond to inhibition by prenyltransferase inhibitors. Site-directed mutagenesis of the key residues involved in ALDH9A1 activity indicates that the catalytic C288 bears the isoprenoid modification likely through an NAD+-dependent mechanism. Furthermore, the isoprenoid modification is also susceptible to hydrolysis, indicating a reversible modification. We hypothesize that this modification originates from endogenous farnesal or geranygeranial, the established degradation products of prenylated proteins and results in a thioester form that accumulates. This novel reversible prenoyl modification on ALDH9A1 expands the current paradigm of protein prenylation by illustrating a potentially new type of protein-lipid modification that may also serve as a novel mechanism for controlling enzyme function.

| S-EPMC10619140 | biostudies-literature

Oncogenic ETS proteins regulate a Ras/MAPK gene expression program in the absence of MAPK signaling

Project description:Approximately 50% of prostate cancers have chromosomal translocations resulting in the over-expression one of four ETS family transcription factors. However, it is not known why these four four family members are selected for oncogenic roles, while other ETS proteins are not. We found that the four oncogenic ETS family members have a specific role in prostate cell migration. Using chromatin immunoprecipitation coupled with next-generation sequencing, this specific biological function was matched to a specific set of genomic targets highlighted by the presence of an AP-1 binding site. ETS/AP-1 binding sites are prototypical Ras-responsive elements, but oncogenic ETS proteins could activate a Ras/MAPK transcriptional program in the absence of MAPK activation. These findings indicate that the specific function of ETS proteins over-expressed in prostate cancer is the activation of a Ras/MAPK gene expression program in the absence of signaling pathway mutations. 16 samples were analyzed, comprised of four replicates each of four different biological conditions. RNA from U0126 treated RWPE-1 empty vector cell RNA serves as a control for each experiment. Cell lines have retroviral expression constructs expressing either empty vector, Flag-ERG, or Flag-ETV1.

2011-10-18 | E-GEOD-29438 | biostudies-arrayexpress

Mitochondrial division is requisite to RAS-induced transformation and targeted by oncogenic MAPK pathway inhibitors.

Project description:Mitochondrial division is essential for mitosis and metazoan development, but a mechanistic role in cancer biology remains unknown. Here, we examine the direct effects of oncogenic RAS(G12V)-mediated cellular transformation on the mitochondrial dynamics machinery and observe a positive selection for dynamin-related protein 1 (DRP1), a protein required for mitochondrial network division. Loss of DRP1 prevents RAS(G12V)-induced mitochondrial dysfunction and renders cells resistant to transformation. Conversely, in human tumor cell lines with activating MAPK mutations, inhibition of these signals leads to robust mitochondrial network reprogramming initiated by DRP1 loss resulting in mitochondrial hyper-fusion and increased mitochondrial metabolism. These phenotypes are mechanistically linked by ERK1/2 phosphorylation of DRP1 serine 616; DRP1(S616) phosphorylation is sufficient to phenocopy transformation-induced mitochondrial dysfunction, and DRP1(S616) phosphorylation status dichotomizes BRAF(WT) from BRAF(V600E)-positive lesions. These findings implicate mitochondrial division and DRP1 as crucial regulators of transformation with leverage in chemotherapeutic success.

| S-EPMC4320323 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data