Proteins 331

• Formin


  Actin acessory protein, nucleates assembly, polymerization promoting, plus end capping protein
• Thymosin


  Actin acessory protein, binds subunits, prevents assembly and prevents polymerization, can’t bind to either end, can’t hydrolyze of exchange ATP
• Tropomodulin


  Actin accessory protein, prevents assembly and disassembly at the minus end (caps)
• Cofilin


  Actin accessory protein, binds ADP-actin filaments, accelerates disassembly, actin depolymerizing
• Gelsolin


  Actin acessory protein, Severs filaments In half, and binds to plus end, activated by cytosolic Ca2+
• Capping Protein 


  Actin acessory protein, Prevents assembly and disassembly at plus end
• Tropomyosin 


  Actin accessory protein, stabilizes filament, modulates binding of other acessory proteins, binds alongside actin
• Profilin


  Actin acessory protein, Binds monomers, concentrates them at sites of filament assembly, promotes polymerization
• Arp 2/3 complex


  Actin acessory protein, nucleates assembly to form a branched network and remains associated with the minus end. Minus end capping protein
• Fimbrin


  Actin acessory protein, non contractile, cross-linking protein that creates tightly packed bundles and excludes myosin. Bundling protein
• Alpha Actinin 


  Actin acessory protein, contractile, bundles actin filaments more loosely and allows myosin entry. Bundling protein
• Myosin II


  Actin motor protein, interacts with actin to make contractile filaments. Bundling protein
• Filamin


  Gel-forming protein, makes a loose and highly viscous actin gel that clamps actin filaments
• Spectrin


  Binds short actin filaments and creates a web of actin, attaches to peripheral membrane proteins, which then attach to integral membrane proteins
• ERM Family 


  Organize membrane domains, regulate signal transduction pathways, and bridge transmembrane proteins
• Gamma-TuRC


  MT accessory protein, nucleates assembly and remains associated with the minus end (caps minus end)
• stathmin


  Mt acessory protein, binds subunits, prevents assembly
• kinesin-13


  Mt acessory protein, induces catastrophe and disassembly, pries ends apart which lower activation energy, promotes depolymerization
• katanin


  Mt acessory proteins, severs microtubules
• MAP2


  Mt acessory protein, filament bundling and cross-linking
• Plectin


  MT acessory protein, links to intermediate filaments
• Tau


  Mt acessory protein
• MAPs


  Mt acessory proteins, Stabilize microtubules by binding along sides, mediate Mt interactions, and regulate how tightly they are bundled
• XMAP215


  Mt acessory protein, Stabilizes plus ends, promotes rapid microtubule growth, binds free tubulin subunits and delivers to + end
• +TIPs


  Mt acessory protein, associate with growing plus ends and can link them to other structures, such as membranes. Plus end tracking proteins (kinesin13 & XMAP215)
• augmin


  Mt acessory protein, nucleates microtubule branching
• Kinesins


  Superfamily of motor proteins
• Dyneins


  Motor proteins specific for the minus end