Vezikulát

Vezikulát, also known as vesicular transport or vesicle-mediated transport, is a fundamental process in cellular biology that facilitates the movement of molecules between different cellular compartments or between the cell interior and its exterior. This mechanism relies on the formation, transport, and fusion of small membrane-bound sacs called vesicles, which encapsulate cargo such as proteins, lipids, or nucleic acids.

Vesicles originate from specific donor membranes, such as the Golgi apparatus, endoplasmic reticulum, or plasma membrane, and are transported along cytoskeletal tracks—typically microtubules or actin filaments—by motor proteins like kinesin, dynein, or myosin. The directionality of transport is determined by the type of motor protein involved; for example, kinesin generally moves vesicles toward the cell periphery, while dynein directs them toward the cell center.

The process begins with the budding of a vesicle from a donor membrane, a step mediated by coat proteins such as COPII (for ER-to-Golgi transport), COPI (for Golgi-to-ER transport), or clathrin (for endocytosis or transcytosis). These coats help deform the membrane and recruit cargo receptors. Once formed, vesicles fuse with their target membranes through a series of interactions involving SNARE proteins, which ensure specificity and prevent random fusion events. Rab proteins, a family of GTPases, also play a critical role in vesicle targeting by labeling vesicles and tethering them to the correct membrane.

Vezikulát is essential for various cellular functions, including secretion, endocytosis, intracellular trafficking, and signal transduction. Dysregulation of vesicular transport can lead to pathological conditions, such as neurodegenerative diseases, metabolic disorders, or immune deficiencies. Advances in microscopy and molecular biology have significantly enhanced the understanding of this process, revealing its complexity and highlighting its importance in maintaining cellular homeostasis.