Use of transcriptomic data to support organelle proteomic analysis.

Genome-wide transcriptional profiling provides a rich source of data for the validation and annotation of organelle proteomic data. Organelle biogenesis is in most cases accompanied by upregulation of genes encoding organelle-specific proteins. Consequently, identification of genes whose expression correlates with organelle assembly leads to a candidate list that can be cross-checked with a preliminary organelle proteome. When proteins are found in the proteome and the corresponding genes are found to have organelle assembly-correlated expression, this greatly increases our confidence that those proteins are true components of the organelle and not contamination. Such an approach can be used to narrow down a preliminary proteomic data set and help us to focus on a smaller sub-set of proteins that are supported by transcriptomic cross-validation.