title: Decreased dicer expression enhances SRP-mediated protein targeting.
abstract: We have shown that Dicer processes 7SL RNA into different fragments ranging from ∼20 to more than 200 nucleotides. Here we addressed the molecular functions of these 7SL RNA fragments and found that some of them functioned as dominant-negative regulators of the full-length 7SL RNA, interfering with signal recognition particle (SRP) complex formation. Transfection of these 7SL RNA fragments inhibited the expression of cell surface glycoproteins, the targeting of a reporter protein to the endoplasmic reticulum, and the secretion of secreted alkaline phosphatase. These results suggest that some Dicer-processed 7SL RNA fragments interfered with SRP-mediated protein targeting. Moreover, we showed that Dicer knockdown enhanced SRP-mediated protein targeting and that transfection of a mixture of the 7SL RNA fragments partially restored this effect. Our data indicate that Dicer can fine-tune the efficiency of SRP-mediated protein targeting via processing a proportion of 7SL RNA into fragments of different lengths.
authors.affiliation: Institute of Genomic Medicine, Wenzhou Medical College, Wenzhou, Zhejiang Province, PR China.
authors.forename: Yong-Feng
authors.initials: YF
authors.lastname: Ren
authors.forename: Guiling
authors.initials: G
authors.lastname: Li
authors.forename: Yong-Feng
authors.initials: YF
authors.lastname: Xue
authors.forename: Xue-Jiao
authors.initials: XJ
authors.lastname: Zhang
authors.forename: Yi-Jiang
authors.initials: YJ
authors.lastname: Song
authors.forename: Lu
authors.initials: L
authors.lastname: Lv
authors.forename: Jianmin
authors.initials: J
authors.lastname: Wu
authors.forename: Yu-Xiao
authors.initials: YX
authors.lastname: Fang
authors.forename: Yu-Qun
authors.initials: YQ
authors.lastname: Wang
authors.forename: Ke-Qing
authors.initials: KQ
authors.lastname: Shi
authors.forename: Yong-Ping
authors.initials: YP
authors.lastname: Chen
authors.forename: Kai-Fu
authors.initials: KF
authors.lastname: Tang
mesh_terms: D002460:Cell Line; D053487:DEAD-box RNA Helicases / Q000235:genetics*; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006801:Humans; D046912:Multiprotein Complexes / Q000378:metabolism; D021381:Protein Transport; D020733:RNA, Small Cytoplasmic / Q000235:genetics / Q000378:metabolism; D043244:Ribonuclease III / Q000235:genetics*; D018271:Signal Recognition Particle / Q000235:genetics / Q000378:metabolism*
chemical_list: C115990:7SL RNA; D046912:Multiprotein Complexes; D020733:RNA, Small Cytoplasmic; D018271:Signal Recognition Particle; C408087:DICER1 protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases