title: Gene-specific correlation of RNA and protein levels in human cells and tissues.
abstract: An important issue for molecular biology is to establish whether transcript levels of a given gene can be used as proxies for the corresponding protein levels. Here, we have developed a targeted proteomics approach for a set of human non-secreted proteins based on parallel reaction monitoring to measure, at steady-state conditions, absolute protein copy numbers across human tissues and cell lines and compared these levels with the corresponding mRNA levels using transcriptomics. The study shows that the transcript and protein levels do not correlate well unless a gene-specific RNA-to-protein (RTP) conversion factor independent of the tissue type is introduced, thus significantly enhancing the predictability of protein copy numbers from RNA levels. The results show that the RTP ratio varies significantly with a few hundred copies per mRNA molecule for some genes to several hundred thousands of protein copies per mRNA molecule for others. In conclusion, our data suggest that transcriptome analysis can be used as a tool to predict the protein copy numbers per cell, thus forming an attractive link between the field of genomics and proteomics.
authors.affiliation: Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Edfors
authors.affiliation: Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Frida
authors.initials: F
authors.lastname: Danielsson
authors.affiliation: Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Björn M
authors.initials: BM
authors.lastname: Hallström
authors.affiliation: Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Lukas
authors.initials: L
authors.lastname: Käll
authors.affiliation: Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Emma
authors.initials: E
authors.lastname: Lundberg
authors.affiliation: Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
authors.forename: Fredrik
authors.identifier: http://orcid.org/0000-0003-0703-3940
authors.initials: F
authors.lastname: Pontén
authors.affiliation: Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Forsström
authors.affiliation: Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden mathias.uhlen@scilifelab.se.|Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark.
authors.forename: Mathias
authors.identifier: http://orcid.org/0000-0002-4858-8056
authors.initials: M
authors.lastname: Uhlén
mesh_terms: D002460:Cell Line; D015870:Gene Expression; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D020543:Proteome / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods*
chemical_list: D020543:Proteome
keywords: gene expression; protein quantification; targeted proteomics; transcriptomics