... the expression of variousalternative reading frame proteins (ARFPs), alsonamed Core+1 proteins, resulting from mechanismssuch as ribosomal frame shifting and internal initiationat alternative ... spectrometersource with a syringe pump (Harvard Type 55 1111; Har-vard Apparatus, South Natick, MA, USA) at a flow rate of 5 lLÆmin)1. Calibration was achieved in the positive ionmode, using denaturated ... forperforming MS analysis, A. Kakkanas and E. Asla-noglou for their help in raising during antibodies, and A. Chappelle for technical support. We are grateful to A. Atkinson and M A. Delsuc...