title: Identification in the rat brain of a set of nuclear proteins interacting with H1° mRNA.
abstract: Synthesis of H1° histone, in the developing rat brain, is also regulated at post-transcriptional level. Regulation of RNA metabolism depends on a series of RNA-binding proteins (RBPs); therefore, we searched for H1° mRNA-interacting proteins. With this aim, we used in vitro transcribed, biotinylated H1° RNA as bait to isolate, by a chromatographic approach, proteins which interact with this mRNA, in the nuclei of brain cells. Abundant RBPs, such as heterogeneous nuclear ribonucleoprotein (hnRNP) K and hnRNP A1, and molecular chaperones (heat shock cognate 70, Hsc70) were identified by mass spectrometry. Western blot analysis also revealed the presence of cold shock domain-containing protein 2 (CSD-C2, also known as PIPPin), a brain-enriched RBP previously described in our laboratory. Co-immunoprecipitation assays were performed to investigate the possibility that identified proteins interact with each other and with other nuclear proteins. We found that hnRNP K interacts with both hnRNP A1 and Hsc70 whereas there is no interaction between hnRNP A1 and Hsc70. Moreover, CSD-C2 interacts with hnRNP A1, Y box-binding protein 1 (YB-1), and hnRNP K. We also have indications that CSD-C2 interacts with Hsc70. Overall, we have contributed to the molecular characterization of a ribonucleoprotein particle possibly controlling H1° histone expression in the brain.
authors.affiliation: Department of Molecular and Biomolecular Technological Sciences (STEMBIO), University of Palermo, Palermo, Italy. carlomaria.diliegro@unipa.it
authors.forename: C M
authors.initials: CM
authors.lastname: Di Liegro
authors.forename: G
authors.initials: G
authors.lastname: Schiera
authors.forename: P
authors.initials: P
authors.lastname: Proia
authors.forename: P
authors.initials: P
authors.lastname: Saladino
authors.forename: I
authors.initials: I
authors.lastname: Di Liegro
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D050883:HSC70 Heat-Shock Proteins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006657:Histones; D012333:RNA, Messenger