The cardiac conduction system (CCS) comprises critical components responsible for the initiation and coordination of the action potential. Aberrant CCS development can cause conduction abnormalities, including sick sinus syndrome and atrioventricular and bundle branch blocks. Gene Ontology (GO; http://geneontology.org/) is an invaluable global bioinformatics resource which can provide structured, computable knowledge describing the functions of gene products. Many gene products are known be involved in CCS development; however, this information is not comprehensively captured by GO. Our study aimed to describe the specific roles of essential proteins that have been reported in the literature to be involved with development and/or function of the CCS. 14 proteins were prioritised for GO annotation which led to the curation of 15 peer-reviewed primary experimental articles using carefully selected GO terms. 152 descriptive GO annotations, including those describing sinoatrial node and atrioventricular node development were created and submitted to the GO Consortium database. A functional enrichment analysis of the 35 proteins known to have a role in CCS confirmed that this work has improved the in silico interpretation of this CCS dataset. Our contribution to the GO database may help elucidate the key mechanisms involved in CCS disorders as previous annotation projects have focussed predominantly on development of the heart rather than that of the CCS. This work may improve future heart disease investigations applying high-throughput methods such as genome-wide association studies analysis, proteomics and transcriptomics
