A family of proteins related to Spatzle, the toll receptor ligand, are encoded in the Drosophila genome

Parker, JS Mizuguchi, K Gay, NJ

Js. Parker et al., A family of proteins related to Spatzle, the toll receptor ligand, are encoded in the Drosophila genome, PROTEINS, 45(1), 2001, pp. 71-80

34

INGLESE

Article

Biochemistry & Biophysics

PROTEINS-STRUCTURE FUNCTION AND GENETICS

0887-3585 → ACNP

45

1

2001

71 - 80

ISI

0887-3585(20011001)45:1<71:AFOPRT>2.0.ZU;2-U

The Drosophila gene Spatzle encodes the activating ligand for the Toll rece ptor. This signaling pathway is required for dorso-ventral patterning in th e early embryo and an antifungal immune response in larvae and adults. The genome sequence of Drosophila shows that there are a total of eight Toll-li ke receptors and these may function in other aspects of embryonic developme nt and innate immunity. Here we describe five Drosophila homologues of Spat zle (Spz2-6) found using an iterative searching method. All five appear to encode proteins containing neurotrophin-like cystine-knot domains. In addit ion, most retain a characteristic intron-exon structure shared with the pro totype Spatzle gene. This provides evidence that the family arose by ancien t gene duplication events and indicates that the gene products may represen t activating ligands for corresponding Toll receptors. Expression studies s how that only Spz4 is expressed strongly in larvae and adults and thus may be involved in an ancillary antifungal response mediated by Toll-5. By cont rast, Spz6 shows a complex spatial and temporally regulated expression patt ern in the late embryo. Thus the new Toll/Spatzle families of signaling mol ecules may have important roles in other aspects of development and immunit y. (C) 2001 Wiley-Liss, Inc.