Profiline

Ubiquitous, 12-16 kDa large, actin-binding, phylogenetically highly conserved, cytosolic proteins consisting of 125-153 amino acids, which occur in all eukaryotic cells.

In addition to actin, profilins bind phosphoinositides and poly-L-proline, although less frequently.

In humans, profilins probably occur in 3 isoforms. Profilins are, among other things, important for the formation of the cytoskeleton of the cell and have an important function both for the cell mobility of the cell and for the transmission of signals between cells.

The homologies between plant profilins are much higher (about 70%) than between plant and animal (30-40%).

Profilins play an important role in the polymerisation of actin (see cytoskeleton below).

In 1991 Bet v2 (see birch below) was discovered as the first allergenic profilin in birch pollen.

The sensitization rate to proflins varies greatly. In Germany, 10-15% of pollen allergy sufferers are sensitized to proflins. Profilins are also potential food allergens. 70-90% of melon and orange allergy sufferers are sensitised to profilins. It is worth noting that food allergy only occurs in pollen sensitised profilin allergy sufferers.

No clinically relevant cross-reactions are expected between plant and animal profilins.

1. Santos A et al(2011) Profilins: mimickers of allergy or relevant allergens? Int Arch Allergy Immunol 155:191-204.