Membrane localization accelerates association under conditions relevant to cellular signaling

• 成果类型: Article
• 署名作者: Huang, William Y. C.; Boxer, Steven G.; Ferrell Jr, James E.
• 署名单位: Stanford University; Stanford University; Stanford University; Johns Hopkins University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-13284
• DOI: 10.1073/pnas.2319491121
• 发表日期: 2024-03-05
• 关键词: ras activation; diffusion; proteins; binding; differentiation; reduction; kinetics; physics; sos

摘要

Translocation of cytoplasmic molecules to the plasma membrane is commonplace in cell signaling. Membrane localization has been hypothesized to increase intermolecular association rates; however, it has also been argued that association should be faster in the cytosol because membrane diffusion is slow. Here, we directly compare an identical association reaction, the binding of complementary DNA strands, in solution and on supported membranes. The measured rate constants show that for a 10-mu m-radius spherical cell, association is 22- to 33-fold faster at the membrane than in the cytoplasm. The kinetic advantage depends on cell size and is essentially negligible for typical similar to 1 mu m prokaryotic cells. The rate enhancement is attributable to a combination of higher encounter rates in two dimensions and a higher reaction probability per encounter.