PT  - JOURNAL ARTICLE
AU  - Camille Ternet
AU  - Philipp Junk
AU  - Thomas Sevrin
AU  - Simona Catozzi
AU  - Erik Wåhlén
AU  - Johan Heldin
AU  - Giorgio Oliviero
AU  - Kieran Wynne
AU  - Christina Kiel
TI  - Analysis of context-specific KRAS–effector (sub)complexes in Caco-2 cells
AID  - 10.26508/lsa.202201670
DP  - 2023 May 01
TA  - Life Science Alliance
PG  - e202201670
VI  - 6
IP  - 5
4099  - https://www.life-science-alliance.org/content/6/5/e202201670.short
4100  - https://www.life-science-alliance.org/content/6/5/e202201670.full
SO  - Life Sci. Alliance2023 May 01; 6
AB  - Ras is a key switch controlling cell behavior. In the GTP-bound form, Ras interacts with numerous effectors in a mutually exclusive manner, where individual Ras–effectors are likely part of larger cellular (sub)complexes. The molecular details of these (sub)complexes and their alteration in specific contexts are not understood. Focusing on KRAS, we performed affinity purification (AP)–mass spectrometry (MS) experiments of exogenously expressed FLAG-KRAS WT and three oncogenic mutants (“genetic contexts”) in the human Caco-2 cell line, each exposed to 11 different culture media (“culture contexts”) that mimic conditions relevant in the colon and colorectal cancer. We identified four effectors present in complex with KRAS in all genetic and growth contexts (“context-general effectors”). Seven effectors are found in KRAS complexes in only some contexts (“context-specific effectors”). Analyzing all interactors in complex with KRAS per condition, we find that the culture contexts had a larger impact on interaction rewiring than genetic contexts. We investigated how changes in the interactome impact functional outcomes and created a Shiny app for interactive visualization. We validated some of the functional differences in metabolism and proliferation. Finally, we used networks to evaluate how KRAS–effectors are involved in the modulation of functions by random walk analyses of effector-mediated (sub)complexes. Altogether, our work shows the impact of environmental contexts on network rewiring, which provides insights into tissue-specific signaling mechanisms. This may also explain why KRAS oncogenic mutants may be causing cancer only in specific tissues despite KRAS being expressed in most cells and tissues.