Pollen allergen Poa pIX/Phl pVI (IPR001778)

Short name: POA_allergen

Family relationships



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: Lol p 5 and Poa p 9.

Grass pollen allergens are one of the major causes of type I allergies (including allergic rhinoconjunctivitis, allergic bronchial asthma and hayfever), afflicting 15-20% of a genetically predisposed population [PMID: 1702432]. The amino acid sequences of three Poa pratensis (Kentucky bluegrass) pollen allergen cDNA clones (KBG 41, 60 and 31), have been determined [PMID: 1702432]. The clones exhibit a high degree of sequence similarity to one another, minor similarity to other known allergens, and no similarity to other known proteins or genes. The predicted molecular masses of the proteins range from 28.3 to 37.8 kDa [PMID: 1702432]. Northern analysis indicates that expression of the genes is confined to pollen tissue. The results suggest that the clones code for a group of proteins that represent a new and previously uncharacterised group of grass pollen isoallergens, which have been designated Poa p 9 [PMID: 1702432].

The C-terminal fragment, conserved in Poa p 9 proteins, appears to contain epitopes unique to these proteins [PMID: 2051020]. The N-terminal region (IPR002914) of Poa p 9 has been shown to possess epitopes that cross-react with the acidic group V allergens of Phleum pratense (Common timothy) [PMID: 2051020]. Comparison of amino acid sequences of recombinant Poa p 9 proteins with those of Lol p 5 isoallergens revealed a low level of similarity between the N-terminal sequences of these proteins [PMID: 2051020].

GO terms

Biological Process

GO:0016068 type I hypersensitivity

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.