InterPro: IPR002097 Profilin/allergen

Profilin is a small eukaryotic protein that binds to monomeric actin (G-actin) in a 1:1 ratio thus preventing the polymerisation of actin into filaments (F-actin). It can also in certain circumstance promote actin polymerisation. Profilin also binds to polyphosphoinositides such as PIP2. Overall sequence similarity among profilin from organisms which belong to different phyla (ranging from fungi to mammals) is low, but the N-terminal region is relatively well conserved. That region is thought to be involved in the binding to actin.

A protein structurally similar to profilin is present in the genome of Variola virus and Vaccinia virus (gene A42R).

Some of the proteins in this family are allergens. Allergies are hypersensitivity reactions of the immune system to specific substances called allergens (such as pollen, stings, drugs, or food) that, in most people, result in no symptoms. A nomenclature system has been established for antigens (allergens) that cause IgE-mediated atopic allergies in humans [WHO/IUIS Allergen Nomenclature Subcommittee King T.P., Hoffmann D., Loewenstein H., Marsh D.G., Platts-Mills T.A.E., Thomas W. Bull. World Health Organ. 72:797-806(1994)]. This nomenclature system is defined by a designation that is composed of the first three letters of the genus; a space; the first letter of the species name; a space and an arabic number. In the event that two species names have identical designations, they are discriminated from one another by adding one or more letters (as necessary) to each species designation.

The allergens in this family include allergens with the following designations: Ara t 8, Bet v 2, Cyn d 12, Hel a 2, Mer a 1 and Phl p 11.