SGER: The Localization and Structural Analysis of a Botrytis Tyrosinase

University Of Alabama In Huntsville, Huntsville AL

Investigators

Abstract

Tyrosinases are type-3 copper proteins involved in the biosynthesis of melanins. In fungi, tyrosinase activity is generally associated with defense and virulence mechanisms, the formation and stability of spores, and in browning and pigmentation. A tyrosinase was cloned and identified from the Botrytis cinerea BO5.10 genome after homology searches with a human tyrosinase protein sequence. The B. cinerea tyrosinase is predicted to have a nonconventional signal sequence, as determined by SecretomeP software analysis. The presence of a nonconventional signal sequence in a B. cinerea tyrosinase protein raises questions as to the location of this protein in the fungal cell. Nonconventional signal sequences do not appear to transverse the normal secretory pathway, involving the endoplasmic reticulum (ER) > Golgi > vesicles > cell membrane, and have never been observed to be glycosylated. Only a limited number of biological proteins have been shown, experimentally, to enter the non-classical secretory pathway in eukaryotes. Therefore, this study, the characterization of a nonconventional signal sequence in a B. cinerea tyrosinase protein, is vital to our understanding of alternative protein trafficking pathways and their biological significance. The broader impact of this project is that it advances scientific discovery in fungal cellular biology while expanding teaching, training, and learning at the University of Alabama in Huntsville (UAH), an EPSCoR designated institution. The research is a logical extension of genome sequencing and annotation by the Botrytis genome consortium and Sclerotinia research communities; the P.I. is an active participant in the International Botrytis-Sclerotinia Genome Consortium. In addition, graduate students will receive supplemental training in fungal cytological methods in the laboratory of a cytologist at the University of Delaware; this collaboration will allow an initial transfer of cytological technology to the laboratory of the PI. Moreover, the collaboration will expand opportunities for the PI to introduce future cytological exercises into a Cell and Developmental Laboratory course in the department of biological sciences at UAH