title: Analysis of turnover and translation regulatory RNA-binding protein expression through binding to cognate mRNAs.
abstract: RNA-binding proteins (RBPs) that associate with specific mRNA sequences and function as mRNA turnover and translation regulatory (TTR) RBPs are emerging as pivotal posttranscriptional regulators of gene expression. However, little is known about the mechanisms that govern the expression of TTR-RBPs. Here, we employed human cervical carcinoma HeLa cells to test the hypothesis that TTR-RBP expression is influenced posttranscriptionally by TTR-RBPs themselves. Systematic testing of the TTR-RBPs AUF1, HuR, KSRP, NF90, TIA-1, and TIAR led to three key discoveries. First, each TTR-RBP was found to associate with its cognate mRNA and with several other TTR-RBP-encoding mRNAs, as determined by testing both endogenous and biotinylated transcripts. Second, silencing of individual TTR-RBPs influenced the expression of other TTR-RBPs at the mRNA and/or protein level. Third, further analysis of two specific ribonucleoprotein (RNP) complexes revealed that TIA-1 expression was controlled via HuR-enhanced mRNA stabilization and TIAR-repressed translation. Together, our findings underscore the notion that TTR-RBP expression is controlled, at least in part, at the posttranscriptional level through a complex circuitry of self- and cross-regulatory RNP interactions.
authors.affiliation: Laboratory of Cellular and Molecular Biology, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, Maryland 21228, USA.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Pullmann
authors.forename: Hyeon Ho
authors.initials: HH
authors.lastname: Kim
authors.forename: Kotb
authors.initials: K
authors.lastname: Abdelmohsen
authors.forename: Ashish
authors.initials: A
authors.lastname: Lal
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Martindale
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Yang
authors.forename: Myriam
authors.initials: M
authors.lastname: Gorospe
mesh_terms: D020413:3' Untranslated Regions; D019921:Biotinylation; D015153:Blotting, Western; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D039102:Poly(A)-Binding Proteins / Q000378:metabolism; D011233:Precipitin Tests; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D034622:RNA Interference; D012333:RNA, Messenger / Q000032:analysis* / Q000378:metabolism; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D000074019:T-Cell Intracellular Antigen-1; D014162:Transfection
chemical_list: D020413:3' Untranslated Regions; D039102:Poly(A)-Binding Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D000074019:T-Cell Intracellular Antigen-1; C071558:TIA1 protein, human; D049452:Green Fluorescent Proteins