genomes are spatially organized on many levels and the positioning of genes within the nucleus contributes to their proper expression this positioning can also result in the clustering of genes with similar expression patterns a phenomenon sometimes called gene kissing we have found that yeast genes are targeted to the nuclear periphery through interaction of the nuclear pore complex with small cis acting dna zip codes in their promoters our recent study demonstrated that genes with the same zip codes cluster together at the nuclear periphery the zip codes were necessary and sufficient to induce interchromosomal clustering finally we identified a transcription factor put3 that binds to the grs i zip code put3 binds to grs i and is required for both grs i dependent positioning at the nuclear periphery and interchromosomal clustering of grs i targeted genes we speculate that our findings might provide insight into other types of gene kissing some of which also require cis acting dna sequences and trans acting proteins.