Spätzle (gene)


Spätzle or Spaetzle is an evolutionarily-conserved arthropod protein first identified in Drosophila melanogaster. It plays a role in embryonic development and in the insect innate immune response. The name was coined by the Nobel laureate Christiane Nüsslein-Volhard after the Spätzle noodle-like form of homozygous mutant fly larvae.

Structure

Spätzle has a cystine knot structure supported by disulfide bridges, is glycosylated, and naturally forms a homodimer. Multiple forms are produced by alternative splicing. It is produced as a preprotein, and needs to be activated by a serine protease called. The signal sequence spz is first cleaved, followed by the spz fragment, leaving the final spz part as the mature protein.

Function

Homodimeric spz binds to a dimeric toll receptor in fruit flies and related organisms, thus activiating the signaling cascade.

Embryonic development

A component of the toll pathway, spz is involved in the formation of the dorso-ventral axis in embryonic development.