Functional characterisation of a nematode secreted GM2-activator protein.
We have identified a GM2-activator protein (GM2AP) with highly unusual properties secreted by the nematode parasite Trichinella spiralis. Expression in Pichia pastoris resulted in a hyperglycosylated protein of 28 kDa, but the 18 kDa native protein was not glycosylated. The parasite GM2AP does not facilitate degradation of GM2 ganglioside by N-acetyl-beta-hexosaminidase A, although it does inhibit phospholipase D activity. Lack of the former activity might be explained by the absence of a domain implicated in binding to hexosaminidase. In addition, and contrary to data on the human GM2AP, the nematode homologue does not inhibit platelet activating factor-induced calcium mobilisation in neutrophils, but actually enhances mediator-induced chemotaxis.
Division of Cell and Molecular Biology, Biochemistry Building, Imperial College London, South Kensington Campus, London SW7 2AY, UK.
Alexandra F
AF
Bruce
Marie-Pierre
MP
Gares
Murray E
ME
Selkirk
Kleoniki
K
Gounaris
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D049289:G(M2) Activator Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005678:G(M2) Ganglioside / Q000378:metabolism; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010843:Pichia / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017160:Trichinella spiralis / Q000235:genetics / Q000378:metabolism*
D049289:G(M2) Activator Protein; D015801:Helminth Proteins; D005678:G(M2) Ganglioside