title: Increased protein levels of heterogeneous nuclear ribonucleoprotein A2/B1 in fetal Down syndrome brains.
abstract: Heterogeneous nuclear ribonucleoproteins (hnRNPs) are predominantly nuclear RNA-binding proteins that form complexes with RNA polymerase II transcripts. These proteins play pivotal roles in transcription, pre-mRNA processing in the nucleus, cytoplasmic mRNA translation and its turnover. In addition, hnRNPs have been shown to be essential for embryonic development of Drosophila. Here we studied the protein levels of hnRNPs (A2/B1, H and H') in fetal brain with Down syndrome (DS; n = 5) compared to controls (n = 7). We used two-dimensional (2-D) gel electrophoresis, matrix-assisted laser desorption ionization mass spectroscopy (MALDI-MS) and specific software for quantification. hnRNP A2/B1 was significantly increased in fetal DS brain (13.52+/-4.50) compared to controls (9.16+/-1.35), but both hnRNP H and H' were unchanged. Increased hnRNP A2/B1 in fetal DS brain may represent high activity of RNA processing such as RNA trafficking and telomere protection, and/or it could contribute to abnormal development of DS brains. Furthermore, comparable expression of hnRNP H and H' suggest a specific upregulation of hnRNP A2/B.
authors.affiliation: Department of Pediatrics, University of Vienna, Austria.
authors.forename: S H
authors.initials: SH
authors.lastname: Kim
authors.forename: M
authors.initials: M
authors.lastname: Dierssen
authors.forename: J C
authors.initials: JC
authors.lastname: Ferreres
authors.forename: M
authors.initials: M
authors.lastname: Fountoulakis
authors.forename: G
authors.initials: G
authors.lastname: Lubec
mesh_terms: D001921:Brain / Q000002:abnormalities / Q000378:metabolism*; D004314:Down Syndrome / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D005333:Fetus / Q000378:metabolism; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008297:Male; D012326:RNA Splicing; D012261:Ribonucleoproteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014158:Transcription, Genetic
chemical_list: D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012261:Ribonucleoproteins; C439768:hnRNP A2