Database Commons

a catalog of worldwide biological databases

An experimental data handling system has been created as an update to the previous Nucleolar Proteome Database (NOPdb3.0: http://www.lamondlab.com/NOPdb3.0/). This updated system is able to manage large data sets identified by multiple mass spectrometry and has been used to analyse highly purified preparations of human nucleoli from different cell lines. The newly created application includes a dynamic relational database, which is kept up to date by laboratory staff. The data are further annotated with information from specific external sources on the web, including the IPI and Gene Ontology databases. In addition, an Application Programming Interface provides external users with a portal to link into the nucleolar proteome database and hence, gain access to continually updated results. From the initial approximately 700 human proteins identified in the previous iteration of the NOPdb, we have now identified over 50 000 peptides contained in over 4500 human proteins from purified nucleoli, providing enhanced coverage of the nucleolar proteome.

The Nucleolar Proteome Database (NOPdb) archives data on >700 proteins that were identified by multiple mass spectrometry (MS) analyses from highly purified preparations of human nucleoli, the most prominent nuclear organelle. Each protein entry is annotated with information about its corresponding gene, its domain structures and relevant protein homologues across species, as well as documenting its MS identification history including all the peptides sequenced by tandem MS/MS. Moreover, data showing the quantitative changes in the relative levels of approximately 500 nucleolar proteins are compared at different timepoints upon transcriptional inhibition. Correlating changes in protein abundance at multiple timepoints, highlighted by visualization means in the NOPdb, provides clues regarding the potential interactions and relationships between nucleolar proteins and thereby suggests putative functions for factors within the 30% of the proteome which comprises novel/uncharacterized proteins. The NOPdb (http://www.lamondlab.com/NOPdb) is searchable by either gene names, nucleotide or protein sequences, Gene Ontology terms or motifs, or by limiting the range for isoelectric points and/or molecular weights and links to other databases (e.g. LocusLink, OMIM and PubMed).