@article{SaffertAdamlaSchiewecketal.2016, author = {Saffert, Paul and Adamla, Frauke and Schieweck, Rico and Atkins, John F. and Ignatova, Zoya}, title = {An Expanded CAG Repeat in Huntingtin Causes+1 Frameshifting}, series = {The journal of biological chemistry}, volume = {291}, journal = {The journal of biological chemistry}, publisher = {American Society for Biochemistry and Molecular Biology}, address = {Bethesda}, issn = {0021-9258}, doi = {10.1074/jbc.M116.744326}, pages = {18505 -- 18513}, year = {2016}, abstract = {Maintenance of triplet decoding is crucial for the expression of functional protein because deviations either into the -1 or +1 reading frames are often non-functional. We report here that expression of huntingtin (Htt) exon 1 with expanded CAG repeats, implicated in Huntington pathology, undergoes a sporadic +1 frameshift to generate from the CAG repeat a trans-frame AGC repeat-encoded product. This +1 recoding is exclusively detected in pathological Htt variants, i.e. those with expanded repeats with more than 35 consecutive CAG codons. An atypical +1 shift site, UUC C at the 5 end of CAG repeats, which has some resemblance to the influenza A virus shift site, triggers the +1 frameshifting and is enhanced by the increased propensity of the expanded CAG repeats to form a stem-loop structure. The +1 trans-frame-encoded product can directly influence the aggregation of the parental Htt exon 1.}, language = {en} } @misc{BenteleSaffertRauscheretal.2013, author = {Bentele, Kajetan and Saffert, Paul and Rauscher, Robert and Ignatova, Zoya and Bluethgen, Nils}, title = {Efficient translation initiation dictates codon usage at gene start}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {912}, issn = {1866-8372}, doi = {10.25932/publishup-44133}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-441337}, pages = {12}, year = {2013}, abstract = {The genetic code is degenerate; thus, protein evolution does not uniquely determine the coding sequence. One of the puzzles in evolutionary genetics is therefore to uncover evolutionary driving forces that result in specific codon choice. In many bacteria, the first 5-10 codons of protein-coding genes are often codons that are less frequently used in the rest of the genome, an effect that has been argued to arise from selection for slowed early elongation to reduce ribosome traffic jams. However, genome analysis across many species has demonstrated that the region shows reduced mRNA folding consistent with pressure for efficient translation initiation. This raises the possibility that unusual codon usage is a side effect of selection for reduced mRNA structure. Here we discriminate between these two competing hypotheses, and show that in bacteria selection favours codons that reduce mRNA folding around the translation start, regardless of whether these codons are frequent or rare. Experiments confirm that primarily mRNA structure, and not codon usage, at the beginning of genes determines the translation rate.}, language = {en} } @article{BenteleSaffertRauscheretal.2013, author = {Bentele, Kajetan and Saffert, Paul and Rauscher, Robert and Ignatova, Zoya and Bluethgen, Nils}, title = {Efficient translation initiation dictates codon usage at gene start}, series = {Molecular systems biology}, volume = {9}, journal = {Molecular systems biology}, number = {6}, publisher = {Nature Publ. Group}, address = {New York}, issn = {1744-4292}, doi = {10.1038/msb.2013.32}, pages = {10}, year = {2013}, abstract = {The genetic code is degenerate; thus, protein evolution does not uniquely determine the coding sequence. One of the puzzles in evolutionary genetics is therefore to uncover evolutionary driving forces that result in specific codon choice. In many bacteria, the first 5-10 codons of protein-coding genes are often codons that are less frequently used in the rest of the genome, an effect that has been argued to arise from selection for slowed early elongation to reduce ribosome traffic jams. However, genome analysis across many species has demonstrated that the region shows reduced mRNA folding consistent with pressure for efficient translation initiation. This raises the possibility that unusual codon usage is a side effect of selection for reduced mRNA structure. Here we discriminate between these two competing hypotheses, and show that in bacteria selection favours codons that reduce mRNA folding around the translation start, regardless of whether these codons are frequent or rare. Experiments confirm that primarily mRNA structure, and not codon usage, at the beginning of genes determines the translation rate.}, language = {en} }