title: Comparative gene expression profiling of in vitro differentiated megakaryocytes and erythroblasts identifies novel activatory and inhibitory platelet membrane proteins.
abstract: To identify previously unknown platelet receptors we compared the transcriptomes of in vitro differentiated megakaryocytes (MKs) and erythroblasts (EBs). RNA was obtained from purified, biologically paired MK and EB cultures and compared using cDNA microarrays. Bioinformatical analysis of MK-up-regulated genes identified 151 transcripts encoding transmembrane domain-containing proteins. Although many of these were known platelet genes, a number of previously unidentified or poorly characterized transcripts were also detected. Many of these transcripts, including G6b, G6f, LRRC32, LAT2, and the G protein-coupled receptor SUCNR1, encode proteins with structural features or functions that suggest they may be involved in the modulation of platelet function. Immunoblotting on platelets confirmed the presence of the encoded proteins, and flow cytometric analysis confirmed the expression of G6b, G6f, and LRRC32 on the surface of platelets. Through comparative analysis of expression in platelets and other blood cells we demonstrated that G6b, G6f, and LRRC32 are restricted to the platelet lineage, whereas LAT2 and SUCNR1 were also detected in other blood cells. The identification of the succinate receptor SUCNR1 in platelets is of particular interest, because physiologically relevant concentrations of succinate were shown to potentiate the effect of low doses of a variety of platelet agonists.
authors.affiliation: Department of Haematology, University of Cambridge, Cambridge, UK.
authors.forename: Iain C
authors.initials: IC
authors.lastname: Macaulay
authors.forename: Marloes R
authors.initials: MR
authors.lastname: Tijssen
authors.forename: Daphne C
authors.initials: DC
authors.lastname: Thijssen-Timmer
authors.forename: Arief
authors.initials: A
authors.lastname: Gusnanto
authors.forename: Michael
authors.initials: M
authors.lastname: Steward
authors.forename: Philippa
authors.initials: P
authors.lastname: Burns
authors.forename: Cordelia F
authors.initials: CF
authors.lastname: Langford
authors.forename: Peter D
authors.initials: PD
authors.lastname: Ellis
authors.forename: Frank
authors.initials: F
authors.lastname: Dudbridge
authors.forename: Jaap-Jan
authors.initials: JJ
authors.lastname: Zwaginga
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Watkins
authors.forename: C Ellen
authors.initials: CE
authors.lastname: van der Schoot
authors.forename: Willem H
authors.initials: WH
authors.lastname: Ouwehand
mesh_terms: D002454:Cell Differentiation / Q000502:physiology*; D004900:Erythroblasts / Q000166:cytology / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008533:Megakaryocytes / Q000166:cytology / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010980:Platelet Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D010980:Platelet Membrane Glycoproteins