The Lepidopteran endoribonuclease-U domain protein P102 displays dramatically reduced enzymatic activity and forms functional amyloids.

"thus our results suggest that the amyloid-mediated melanin synthesis in the defense against intruders is a conserved mechanism within the order lepidoptera and that there could be an association between the loss of ancestral enzymatic rna cleavage activity and the ability of the lepidopteran alternative xendou-like proteins to form amyloids2 2 1 database searches were performed using the nucleotide and the amino acid sequences of p102 (genbank ids: fr751090 1 and cby85302 1 respectively) and the blast algorithm available at the national center for biotechnology information (ncbi) ( http://www ncbi nlm nih gov/ )."

"5 Conflict of interest All authors declare no conflict of interest."

"This work was supported by the Italian Ministry of University and Research (MiUR), in the framework of a national research program (PRIN 2008FBJPR8). We would like to thank Prof. Angharad Gatehouse (Newcastle University, UK) and Prof. Magda de Eguileor (University of Insubria, Varese, Italy) for their critical reading of the manuscript, Dr. Elisa Caffarelli (CNR, Rome, Italy) for providing the recombinant XendoU used in enzymatic activity assays, Dr. Pietro Laneve for providing the cDNA coding for Xendo U Dr. Gennaro Sansone for realizing the graphical abstract, Dr. Teresa Zotta (University of Basilicata, Potenza, Italy) for providing the GelCompar II software and Luca Trotti for Heliothis virescens picture."