AUF1 and HuR proteins stabilize interleukin-8 mRNA in human saliva.
Human saliva contains thousands of mRNAs, some of which have translational value as diagnostic markers for human diseases. We have found that more than 30% of the mRNAs detected in human saliva contain AU-rich elements (ARE) in their 3' untranslated regions (3'UTR). Since AREs are known to contribute to RNA turnover by forming complexes with ARE-binding proteins, we hypothesized that salivary mRNA stability is mediated by ARE-binding proteins in human saliva. To test this hypothesis, we monitored the in vitro degradation of a radiolabeled ARE-containing salivary mRNA (IL-8) in salivary protein extracts. The degradation of IL-8 mRNA was accelerated by competition for saliva ARE-binding proteins through the addition of excess unlabeled IL-8 mRNA fragments containing 4 tandem AREs. UV cross-linking and immunoprecipitation experiments revealed 2 ARE-binding proteins, AUF1 and HuR, associated with IL-8 mRNA in saliva. These results demonstrate that ARE-binding proteins contribute to the stability of ARE mRNAs in human saliva.
Palanisamy
V
V
School of Dentistry and Dental Research Institute, University of California Los Angeles, Los Angeles, CA 90095-1668, USA.
Park
N J
NJ
Wang
J
J
Wong
D T
DT
D000954:Antigens, Surface / Q000378:metabolism*; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D / Q000378:metabolism*; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D020871:RNA Stability / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D012016:Reference Values; D012463:Saliva / Q000378:metabolism*
D000954:Antigens, Surface; D051959:ELAV Proteins; D000067780:ELAV-Like Protein 1; C098770:ELAVL1 protein, human; C000630986:HNRNPD protein, human; D000081035:Heterogeneous Nuclear Ribonucleoprotein D0; D034502:Heterogeneous-Nuclear Ribonucleoprotein D; D016209:Interleukin-8; D012333:RNA, Messenger; D016601:RNA-Binding Proteins