From Transcript to Protein

is currently being directed toward identifying the protein components of spliceosomes, determining how they in-Meyerhofstrasse 1 Postfach 102209 teract with pre-mRNA and with each other during the splicing reaction, and analyzing how these interactions D69117 Heidelberg Germany are regulated. tut Pasteur, Paris) reported studies on how 5Ј splice sites and branch sites in budding yeast pre-mRNAs are Dundee DD1 4HN United Kingdom recognized by splicing factors. Legrain described an exhaustive mutagenesis of the branch point consensus sequence, analyzed using an in vivo assay system, which showed that certain base substitutions could dif-One of the most interesting formats for a scientific meet-ferentially affect the splicing of pre-mRNA and its trans-ing involves bringing together researchers working in port out of the nucleus. Although base pairing at the overlapping or closely related fields where the opportu-branch point between the pre-mRNA and U2 snRNA nity can arise for cross-fertilization and exchange of is essential for splicing, it is apparently not linked to ideas. This was the aim of the recent workshop on mRNA retention of unspliced pre-mRNA in the nucleus. Legrain processing, transport, and translation held at the Juan reported that mutational data also point to an important March Foundation in Madrid on March 11–13. All the RNA–protein interaction taking place at the nucleotide fields represented shared a common interest in studying immediately upstream of the branch site consensus, the synthesis, maturation, transport, stability, and func-where a U residue is moderately conserved. B. Seraphin tion of mRNA. The presentations included talks on char-(EMBL, Heidelberg) described how the mechanism for acterizing the machineries involved in splicing, polyade-selecting the precise site of cleavage at the 5Ј intron– nylating, and translating mRNA; how RNAs and proteins exon junction involves a complex network of snRNA– are transported into and out of the nucleus; how post-pre-mRNA base pairing. First, the region to be cleaved translational mechanisms can control gene expression; is selected by base pairing between the 5Ј terminus of and how RNA mechanisms are involved in virus–host U1 snRNA and the pre-mRNA. Subsequently, both U5 interactions. The venue was ideal, our hosts were gener-and U6 snRNAs participate in selecting the exact bond ous and helpful, and the outcome was a tremendously to be cleaved by base pairing to the pre-mRNA. Seraphin stimulating meeting where every talk was followed by pointed out that there may be some redundancy in this an in-depth, open discussion, usually lasting 10–15 mi-mechanism, as …