title: Miniature protein ligands for EVH1 domains: interplay between affinity, specificity, and cell motility.
abstract: Dynamic rearrangements of the actin cytoskeleton power cell motility in contexts ranging from intracellular microbial pathogenesis to axon guidance. The Ena/VASP family proteins-Mena, VASP, and Evl-are believed to control cell motility by serving as a direct link between signaling events and the actin cytoskeleton. It has previously been reported that a novel miniature protein, pGolemi, binds with high affinity to the EVH1 domain of Mena (Mena1-112) but not to those of VASP (VASP1-115) or Evl (Evl1-115) and also causes an unusual defect in actin-driven Listeria monocytogenes motility. Here, scanning mutagenesis was used to examine the effects of single amino acid changes within pGolemi on EVH1 domain affinity and specificity, miniature protein secondary structure, and L. monocytogenes motility. The data suggest that pGolemi contains the expected aPP-like fold and binds Mena1-112 in a manner highly analogous to the proline-rich repeat region of L. monocytogenes ActA protein. Residues throughout pGolemi contribute to both EVH1 domain affinity and paralog specificity. Moreover, the affinities of pGolemi variants for Mena1-112 correlate with selectivity against the EVH1 domains of VASP and Evl. In L. monocytogenes motility assays, speed and speed variability correlate strongly with EVH1 paralog specificity, suggesting that the Ena/VASP paralogs do not play equivalent roles in the process of L. monocytogenes actin tail maturation.
authors.affiliation: Department of Chemistry, Yale University, New Haven, Connecticut 06520, USA.
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Holtzman
authors.forename: Kamil
authors.initials: K
authors.lastname: Woronowicz
authors.forename: Dasantila
authors.initials: D
authors.lastname: Golemi-Kotra
authors.forename: Alanna
authors.initials: A
authors.lastname: Schepartz
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D001665:Binding Sites; D002465:Cell Movement; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008024:Ligands; D008089:Listeria monocytogenes / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008840:Microfilament Proteins / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010191:Pancreatic Polypeptide / Q000737:chemistry* / Q000378:metabolism; D011392:Proline / Q000737:chemistry / Q000378:metabolism; D017510:Protein Folding; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C092744:ENA-VASP proteins; D008024:Ligands; D008565:Membrane Proteins; D008840:Microfilament Proteins; C072980:actA protein, Listeria monocytogenes; C009725:pancreatic polypeptide, avian; D010191:Pancreatic Polypeptide; D011392:Proline