Notes: The full-length 3´ UTR of mouse RNA-binding protein HuR was amplified and cloned into psiCHECK™-1 Vector to create pEM429 plasmid. To generate radiolabeled RNA substrates for use in cleavage assays, RNA was synthesized from 1µg of linearized plasmid using 50µCi of [α-³²P]UTP, 0.8mM Ribo m⁷G Cap Analog and T7 RNA Polymerase by incubating for 1.5 hours at 37°C. The RNAs were then treated with 1 unit of RQ1 RNase-Free DNase per 1µg of template DNA for 15 minutes at 37°C before extracting with phenol:chloroform, precipitating with ethanol and resuspending in DEPC-treated water. The cleavage assay used 60fmol of ³²P-labeled substrate RNA with 10U Recombinant RNAsin Ribonuclease Inhibitor in a reaction incubated for 2.5 hours at 30°C. RNA probes were labeled with biotin using T7 or T3 RNA Polymerases with a biotin-UTP labeling NTP mixture and incubated for 2 hours at 37°C. The biotinylation reaction was then treated with RQ1 RNase-Free DNase following the same protocol used for radiolabeled RNA. To form HuR/RNA complexes, 2µg of biotinylated RNA was mixed with 100µg nuclear extract and 40 units Recombinant RNAsin^® Ribonuclease Inhibitor in a total volume of 20µl, and incubated for 30 minutes at room temperature. For CstF-64/RNA complexes, 1µg of biotinylated RNA was used and the complexes were stabilized by UV crosslinking using 10U Recombinant RNAsin Ribonuclease Inhibitor during the UV treatment. NIH 3T3 cells were UV crosslinked and either total or nuclear RNA used for immunoprecipitation. After extraction the RNAs were treated with RQ1 RNase-Free DNase for 15 minutes at 37°C before RT-PCR using HuR-specific primers. Total RNA purified from cultured cells were incubated with 50U/ml RQ1 RNase-Free DNase at 37°C for 30 minutes before use in RT-qPCR. (4187)

Notes: The authors investigated common variants of the APOA5 gene that have been associated with differences in plasma triglyceride (TG) levels. PCR fragments containing either the –1131T --> C promoter variant or containing both the –1131T --> C and –3G --> A promoter variants were cloned into the pGEM^®-T Vector System. The fragments were subsequently cloned into the pGL3 Basic Vector and transiently transfected into Huh7 and HepG2 cells along with the luciferase control vector, pRL-TK. The cells were lysed 48 hours after transfection and Luciferase activity was measured with the Dual-Luciferase^® Reporter Assay System. The function of the 1891T --> C variant in the 3´ UTR was tested the same way; with the exception that site-directed mutagenesis was performed to introduce the T --> C at position 1891 before the fragment was cloned into the pGL3 Basic Vector. The functionality of the Kozak sequence –3A --> G variant was determined by cloning cDNAs into the pGEM^®-7Zf Vector. Transcription/translation experiments were performed using the TNT^® Quick Coupled Transcription/Translation System and the proteins were labeled using the FluorTect™ Green_Lys System. In addition, a primer extension inhibition assay was performed using capped mRNAs generated with the Riboprobe^® System –T7 and the Ribo m⁷G Cap Analog. Ribosome binding reactions were performed using the Rabbit Reticulocyte Lysate System, Nuclease Treated. (3460)