title: Effects of RhebL1 silencing on the mTOR pathway.
abstract: The insulin/Ras Homolog Enriched in Brain (Rheb)/Mammalian Target of Rapamycin (mTOR) pathway has been implicated in a variety of cancers. The activation of mTOR is regulated by a small G-protein, Rheb1. In mammalian systems there are two Rheb genes--Rheb1 and RhebL1 (Rheb2). The two genes show high sequence homology, however it has yet to be determined whether they are redundant in function. In this study the contribution of RhebL1 toward the mTOR pathway was investigated by transient gene silencing in three cell lines-HEK293, HeLa, and NIH3T3. Both Rheb1 and RhebL1 genes were silenced individually as well as in combination using eleven commercially synthesized siRNAs. Results from cross reactivity experiments showed the silencing of Rheb1 and RhebL1 to be highly specific for their target gene. This is the first report of its kind to examine the function of the endogenous Rheb genes using single and dual silencing. Phosphorylation of the mTOR effector S6 was not affected by RhebL1 silencing as it was by Rheb1 silencing, suggesting for the first time that RhebL1 may be impacting the mTOR pathway in a different manner than Rheb1.
authors.affiliation: Biology Program, California State University Channel Islands, 1 University Drive, Camarillo, CA 93012, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Bonneau
authors.forename: Nitika
authors.initials: N
authors.lastname: Parmar
mesh_terms: D000818:Animals; D001483:Base Sequence; D020868:Gene Silencing; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000172:deficiency*; D041681:NIH 3T3 Cells; D009479:Neuropeptides / Q000172:deficiency*; D010957:Plasmids / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D000076205:Ras Homolog Enriched in Brain Protein; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000235:genetics*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D014162:Transfection; D018631:ras Proteins / Q000172:deficiency*
chemical_list: D009479:Neuropeptides; C490211:RHEB protein, human; C504241:RHEBL1 protein, human; D034741:RNA, Small Interfering; D000076205:Ras Homolog Enriched in Brain Protein; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D020559:Monomeric GTP-Binding Proteins; D018631:ras Proteins