2pav
From Proteopedia
Ternary complex of Profilin-Actin with the Last Poly-Pro of Human VASP
Structural highlights
Disease[PROF1_HUMAN] Defects in PFN1 are the cause of amyotrophic lateral sclerosis 18 (ALS18) [MIM:614808]. A neurodegenerative disorder affecting upper motor neurons in the brain and lower motor neurons in the brain stem and spinal cord, resulting in fatal paralysis. Sensory abnormalities are absent. The pathologic hallmarks of the disease include pallor of the corticospinal tract due to loss of motor neurons, presence of ubiquitin-positive inclusions within surviving motor neurons, and deposition of pathologic aggregates. The etiology of amyotrophic lateral sclerosis is likely to be multifactorial, involving both genetic and environmental factors. The disease is inherited in 5-10% of the cases.[1] Function[ACTS_RABIT] Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells. [VASP_HUMAN] Ena/VASP proteins are actin-associated proteins involved in a range of processes dependent on cytoskeleton remodeling and cell polarity such as axon guidance, lamellipodial and filopodial dynamics, platelet activation and cell migration. VASP promotes actin filament elongation. It protects the barbed end of growing actin filaments against capping and increases the rate of actin polymerization in the presence of capping protein. VASP stimulates actin filament elongation by promoting the transfer of profilin-bound actin monomers onto the barbed end of growing actin filaments. Plays a role in actin-based mobility of Listeria monocytogenes in host cells. Regulates actin dynamics in platelets and plays an important role in regulating platelet aggregation.[2] [3] [4] [5] [6] [7] [PROF1_HUMAN] Binds to actin and affects the structure of the cytoskeleton. At high concentrations, profilin prevents the polymerization of actin, whereas it enhances it at low concentrations. By binding to PIP2, it inhibits the formation of IP3 and DG. Inhibits androgen receptor (AR) and HTT aggregation and binding of G-actin is essential for its inhibition of AR.[8] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCells sustain high rates of actin filament elongation by maintaining a large pool of actin monomers above the critical concentration for polymerization. Profilin-actin complexes constitute the largest fraction of polymerization-competent actin monomers. Filament elongation factors such as Ena/VASP and formin catalyze the transition of profilin-actin from the cellular pool onto the barbed end of growing filaments. The molecular bases of this process are poorly understood. Here we present structural and energetic evidence for two consecutive steps of the elongation mechanism: the recruitment of profilin-actin by the last poly-Pro segment of vasodilator-stimulated phosphoprotein (VASP) and the binding of profilin-actin simultaneously to this poly-Pro and to the G-actin-binding (GAB) domain of VASP. The actin monomer bound at the GAB domain is proposed to be in position to join the barbed end of the growing filament concurrently with the release of profilin. Structural basis for the recruitment of profilin-actin complexes during filament elongation by Ena/VASP.,Ferron F, Rebowski G, Lee SH, Dominguez R EMBO J. 2007 Oct 31;26(21):4597-606. Epub 2007 Oct 4. PMID:17914456[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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