P950Experimental Annotation of Post-Translationally Modified Proteins in Chicken
Experimental Annotation of Post-Translationally Modified Proteins in Chicken
Date: Monday, January 13, 2014
Room: Grand Exhibit Hall
Despite having a sequenced genome and a relatively well characterized proteome, the functional annotation of enzymes and modifications of proteins in chicken is still lacking and requires systematic analysis. The existing protein annotation is in large part limited to computational predictions based on orthology to human or mouse proteins. Experimental annotation of chicken proteins will provide an insight into activities of these proteins, and increase success of studies relevant to chicken health or growth. Post-translational modifications such as ubiquitination and phosphorylation regulate essential cellular processes. Chemical proteomics have become useful in enzyme annotation, including activity-dependent molecular probes used in functional proteomics. Here we describe the identification and annotation of active chicken deubiquitinases (DUBs) that regulate ubiquitination of proteins and kinases that regulate phosphorylation. Ubiquitin-specific active-site probe labeling coupled with quantitative proteomics identified new chicken deubiquitinases, including USP5, USP4, USP25, USP19-like, UCHL5 and UCHL3. Profiling the DUBs in different chicken tissues such as spleen, crop, liver, and proventriculus showed differences in the abundance of DUBs. We used a kinase active-site probe Desthiobiotin-ATP to chemically tag the kinases in chicken macrophages and identified them by mass spectrometry. Several kinases, previously not confirmed at a protein expression level were identified, including tyrosine-protein kinase BAZ1B, tyrosine-protein kinase transforming protein Fps isoform 1, and adenylate kinase 2, mitochondrial. Annotation of active chicken DUBs and kinases reported here could aid post-genome utilization of systems biology approaches to better understand the mechanisms of gene function to improve economics traits of poultry.