title: Quantitative trait loci mapping of the mouse plasma proteome (pQTL).
abstract: A current challenge in the era of genome-wide studies is to determine the responsible genes and mechanisms underlying newly identified loci. Screening of the plasma proteome by high-throughput mass spectrometry (MALDI-TOF MS) is considered a promising approach for identification of metabolic and disease processes. Therefore, plasma proteome screening might be particularly useful for identifying responsible genes when combined with analysis of variation in the genome. Here, we describe a proteomic quantitative trait locus (pQTL) study of plasma proteome screens in an F(2) intercross of 455 mice mapped with 177 genetic markers across the genome. A total of 69 of 176 peptides revealed significant LOD scores (≥5.35) demonstrating strong genetic regulation of distinct components of the plasma proteome. Analyses were confirmed by mechanistic studies and MALDI-TOF/TOF, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses of the two strongest pQTLs: A pQTL for mass-to-charge ratio (m/z) 3494 (LOD 24.9, D11Mit151) was identified as the N-terminal 35 amino acids of hemoglobin subunit A (Hba) and caused by genetic variation in Hba. Another pQTL for m/z 8713 (LOD 36.4; D1Mit111) was caused by variation in apolipoprotein A2 (Apoa2) and cosegregated with HDL cholesterol. Taken together, we show that genome-wide plasma proteome profiling in combination with genome-wide genetic screening aids in the identification of causal genetic variants affecting abundance of plasma proteins.
authors.affiliation: Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University Hospital Leipzig, 04103 Leipzig, Germany.
authors.forename: Lesca M
authors.initials: LM
authors.lastname: Holdt
authors.forename: Annette
authors.initials: A
authors.lastname: von Delft
authors.forename: Alexandros
authors.initials: A
authors.lastname: Nicolaou
authors.forename: Sven
authors.initials: S
authors.lastname: Baumann
authors.forename: Markus
authors.initials: M
authors.lastname: Kostrzewa
authors.forename: Joachim
authors.initials: J
authors.lastname: Thiery
authors.forename: Daniel
authors.initials: D
authors.lastname: Teupser
mesh_terms: D000818:Animals; D016633:Apolipoprotein A-II / Q000235:genetics*; D008076:Cholesterol, HDL / Q000235:genetics; D003433:Crosses, Genetic; D005819:Genetic Markers; D014644:Genetic Variation; D006441:Hemoglobin A / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008970:Molecular Weight; D017434:Protein Structure, Tertiary; D020543:Proteome / Q000737:chemistry / Q000235:genetics*; D040641:Quantitative Trait Loci; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055672:Static Electricity
chemical_list: D016633:Apolipoprotein A-II; D008076:Cholesterol, HDL; D005819:Genetic Markers; D020543:Proteome; D006441:Hemoglobin A