Barbedänden

Barbedänden is the term used in Swedish-language cell biology literature to refer to the barbed end of an actin filament. The barbed end, also called the plus end, is the rapidly elongating terminus of filamentous actin (F-actin), in contrast to the slower-growing pointed (minus) end. In many textbooks the term barbed end is used, while barbedänden appears in specialized Swedish texts.

The barbed end exhibits faster polymerization than the pointed end. Polymerization at this end proceeds when ATP-bound actin monomers add to the filament, and the barbed end has a lower critical concentration for polymerization. This rapid growth is regulated by actin-binding proteins such as profilin, which delivers actin monomers to the barbed end, and CapZ, which can cap the barbed end to modulate elongation. The Arp2/3 complex can nucleate new filaments and create branched networks that extend from existing filaments, contributing to structures like lamellipodia.

Barbed-end dynamics are central to many cellular processes, including cell migration, shape changes during division, endocytosis, and vesicle trafficking. The balance between assembly at the barbed end and disassembly at the pointed end, together with capping and uncapping events, underlies actin turnover and treadmilling in living cells. Disruptions in barbed-end regulation can affect development and are implicated in various diseases, highlighting the importance of precise control by signaling pathways and actin-binding proteins.

Notes: In Swedish-language literature, barbedänden is commonly used to describe the same concept as the English term barbed end.