Overview

1. Dislocation of the frameshift signal uncouples gag and pol reading frames and reveals the role of transframe proteins in HIV-1 replication Andreas Leiherer Molecular Microbiology and Gene Therapy Unit Institute of Medical Microbiology and Hygiene, University of Regensburg Germany Overview

2. HIV genom organisation and reorganisation: uncoupling gag an pol AL: NL4-3 (wt): The gag and pol reading frames are partially overlapping and in addition superimposed by the ribosomal frameshift site on RNA-level • Mutationes in p6* • Alteration in p1 • Alteration of the frame shift siteRNA-structure: Effects on level of translation • no clear-cut statement about the role of p6* protein for viral replication New virus (AL): gag and pol are uncoupled but the virus is still fully functional

3. Functional analysis of p6* 125 CEM ALD-myc 2500 100 ALD ALn AL kDa 75 % Infectivity 2000 VP 75 50 Gag 50 1500 25 ng p24/ml 37 Gag 0 1000 AL ALn ALD mock ALD-myc 25 CA ALD 20 500 ALD-myc AL 75 0   ALn RT 0 5 10 15 20 50 days   RT Infectivity: no influence Precursor production: no influence Replication: deletions in p6* even enhance replication Processing: no influence The p6* sequence - apart from its C-term. cleav. site - is not essential for particle production, precursor processing, infectivity and replicationp6* is a spacer peptide

4. Another frame shift player with unknown function: p1 CEM 750 AL Dp1 CEM 2500 AL Dp1-G-A AL 2000 AL P7L P13L 500 1500 ng p24/ml ng p24/ml 1000 250 ALD 500 ALD-myc AL 0 ALn 0 5 10 15 20 0 days 0 5 10 15 20 25 days P1 is indispensable for virus function and not a spacer like p6*

5. Thank you for your attention Andreas Leiherer Christine Ludwig and Ralf Wagner Molecular Microbiology and Gene Therapy Unit Institute of Medical Microbiology and Hygiene, University of Regensburg Germany end