At stationary phase, a decoupling between protein and transcripts abundance is generally observed except for most of constitutive processes [ 50], supporting our exploration of the transcriptome and proteome of S. aureus during this stage.
Absence of correlation between protein and transcript levels, suggests the post-transcriptional regulation is occurring.
While there was a strong correlation between protein and transcript detection within the same sample, we also identified proteins whose corresponding transcripts were not detected by microarray.
A heat map summarizes the differences and similarities observed between protein and transcript data for selected pathways.
To explore the relationship between protein and transcript abundance in naïve CD4+ T cells, we correlated the iBAQ values of proteins and transcript FPKM values.
In addition, a significant correlation between protein and transcript was observed for RRM1 and TS (r = 0.29 and r = 0.47, resp).
A good correlation between protein and transcript regulation at the necrotrophic stage was observed, indicating the great amplitude of activation of host defense responses.
Necdin protein was absent from most cancer cell lines investigated but as described for other transcripts in other tumour cell lines and tumours (Stark et al, 2006), a direct correlation between protein and transcript levels was not observed.
Poor concordance between protein and transcript expression for cell-surface proteins are consistent with previous studies and, together with our data, suggest that protein is a more reliable predictor of cell-type specificity than RNA expression alone.
For other genes, however, a correlation between protein and transcript level changes is only seen when different time points are compared, probably because new proteins require longer times to be produced.
