CapZ-α2 Activators

CapZ-α2, a subunit of the protein complex CapZ, is an essential component of the actin cytoskeleton of eukaryotic cells. CapZ, also known as F-actin capping protein, is a heterodimer composed of two subunits: α and β, with multiple isoforms of each, including CapZ-α2. This protein complex is ubiquitously expressed and localizes to the fast-growing end (barbed end) of actin filaments, where it performs the crucial function of regulating the assembly and disassembly of actin filaments.

CapZ-α2's primary role is to bind to the barbed ends of actin filaments, thereby preventing the addition or loss of actin monomers at this end of the filament. This capping activity is vital for maintaining the stability and length of actin filaments, which are critical for various cellular processes including cell motility, shape, division, and muscle contraction. By controlling the dynamics of the actin cytoskeleton, CapZ-α2 indirectly influences these cellular functions.The regulation of CapZ-α2, and thus CapZ's activity, is complex and involves various signaling pathways that modulate its capping ability in response to cellular needs. Phosphorylation, binding of phosphoinositides, and interactions with other actin-binding proteins can all affect CapZ's function, either promoting or inhibiting its capping ability.