The protein profilin binds to both actin and the head groups of poly)phosphoinositide)s and may regulate both actin assembly and the phosphoinositide signaling pathway. As a first step in understanding the activity of profilin at the molecular level, we have determined the secondary structure of Acanthamoeba profilin I in solution using multidimensional, heteronuclear NMR spectroscopy. Using a ...

Ena/VASP (vasodialator-stimulated protein) proteins regulate many actin-dependent events, including formation of protrusive structures, fibroblast migration, neurite extension, cell-cell adhesion, and Listeria pathogenesis. In vitro, Ena/VASP activities on actin are complex and varied. They promote actin assembly, protect filaments from cappers, bundle filaments, and inhibit filament branching....

The gram negative rod Shigella flexneri uses it surface protein IcsA to induce host cell actin assembly and to achieve intracellular motility. Yet, the IcsA protein lacks the oligoproline sequences found in ActA, the surface protein required for locomotion of the gram positive rod Listeria monocytogenes. Microinjection of a peptide matching the second ActA oligoproline repeat (FEFPPPPTDE) stops...

Profilins are key factors for dynamic rearrangements of the actin cytoskeleton. However, the functions of profilins in differentiated mammalian cells are uncertain because profilin deficiency is early embryonic lethal for higher eukaryotes. To examine profilin function in chondrocytes, we disrupted the profilin 1 gene in cartilage (Col2pfn1). Homozygous Col2pfn1 mice develop progressive chondro...

Acanthamoeba actophorin is a member of ADF/cofilin family that binds both actin monomers and filaments. We used fluorescence anisotropy to study the interaction of actin monomers with recombinant actophorin labeled with rhodamine on a cysteine substituted for Serine-88. Labeled actophorin retains its affinity for actin and ability to reduce the low shear viscosity of actin filaments. At physiol...

Background: Several studies reported the clinical features of IgE-mediated hypersensitivity after ingestion of melon. Melon allergy is a common IgE-mediated fruit allergy in Iran. This prompted us to investigate immunochemical and molecular properties of the major allergen in melon fruit, to compare the IgE-binding capacity of the natural protein with the recombinant allergen, and to determine ...

The Arp2/3 complex was first purified from Acanthamoeba castellanii by profilin affinity chromatography. The mechanism of interaction with profilin was unknown but was hypothesized to be mediated by either Arp2 or Arp3. Here we show that the Arp2 subunit of the complex can be chemically cross-linked to the actin-binding site of profilin. By analytical ultracentrifugation, rhodamine-labeled prof...

INTRODUCTION Lipid transfer proteins (LTP), profilin and PR-10 are the most important panallergens in central and southern Italy. Lipid transfer proteins are stable molecules, predominantly present in the fruit peel, which can induce systemic symptoms after ingestion of vegetables. Profilin and PR-10 are randomly distributed in the pulp and peel. Both are labile proteins and usually determine r...

BACKGROUND Profilin is a highly conserved protein regarded as a pan-allergen in pollen and vegetable food. Homologous proteins from different sources are highly cross-reactive. OBJECTIVE To assess whether detecting immunoglobulin (Ig) E to multiple profilins from different sources is clinically more useful than detecting IgE to a single representative profilin. METHODS Sera from 43 subjects...

We compared the pattern of replication of two cell-type specific profilin genes in one developmental stage of the slime mold Physarum polycephalum. Taking advantage of the natural synchrony of S-phase within the plasmodium, we established that the actively transcribed profilin P gene is tightly linked to a chromosomal replication origin and is replicated at the onset of S-phase. In contrast, th...