Abstract

Cholesterol is an indispensable component of the eukaryotic cell membrane, critically governing its biophysical properties and the function of numerous cellular processes. This review, titled "Cell Membrane Cholesterol and Regulation of Cellular Processes: New and the Same Old Thing," synthesizes the established roles of cholesterol alongside emerging paradigms in membrane and cell biology. The primary objective is to delineate the molecular mechanisms by which cholesterol's concentration and spatial organization within the lipid bilayer regulate diverse cellular functions, including signal transduction, membrane trafficking, and protein sorting. We employ a systematic review of structural, biophysical, and cell-based studies, focusing on the concept of lipid rafts and non-raft domains. Key findings highlight that while cholesterol's role in modulating membrane fluidity is well-understood, recent research reveals sophisticated, localized interactions with specific proteins and lipids that act as fine-tuning mechanisms for cellular signaling pathways. The significance of this work lies in providing a unified framework for understanding cholesterol's pleiotropic effects, which is crucial for developing therapeutic strategies targeting cholesterol-related pathologies such as neurodegenerative and cardiovascular diseases.