NRas activity is regulated by dynamic interactions with nanoscale signaling clusters at the plasma membrane

Oren Yakovian; Julia Sajman; Michal Alon; Rand Arafeh; Yardena Samuels; Eilon Sherman

doi:10.1016/j.isci.2022.105282

NRas activity is regulated by dynamic interactions with nanoscale signaling clusters at the plasma membrane

iScience. 2022 Oct 9;25(11):105282. doi: 10.1016/j.isci.2022.105282. eCollection 2022 Nov 18.

Authors

Oren Yakovian¹, Julia Sajman¹, Michal Alon², Rand Arafeh^{2

3}, Yardena Samuels², Eilon Sherman¹

Affiliations

¹ Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel.
² Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001 Rehovot, Israel.
³ Department of Molecular Oncology, Dana Farber Cancer Institute, Boston, MA, USA.

Abstract

NRas is a key mediator of the mitogenic pathway in normal cells and in cancer cells. Its dynamics and nanoscale organization at the plasma membrane (PM) facilitate its signaling. Here, we used two-color photoactivated localization microscopy to resolve the organization of individual NRas and associated signaling proteins in live melanoma cells, with resolution down to ∼20 nm. Upon EGF activation, a fraction of NRas and BRAF (dis)assembled synchronously at the PM in co-clusters. NRas and BRAF clusters associated with GPI-enriched domains, serving as possible nucleation sites for these clusters. NRas and BRAF association in mutual clusters was reduced by the NRas farnesylation inhibitor lonafarnib, yet enhanced by the BRAF inhibitor vemurafenib. Surprisingly, dispersed NRas molecules associated with the periphery of self-clusters of either Grb2 or NF1. Thus, NRas-mediated signaling, which is critical in health and disease, is regulated by dynamic interactions with functional clusters of BRAF or other related proteins at the PM.

Keywords: Biological sciences; Biophysics; Cell biology; Molecular biology.