Registry Parts

• urg1 promoter: uracil-regulable urg1 promoter, that allows tight expression control of ectopic genes with otherwise minimal side effects on genome-wide gene expression. Transcription is activated after 5 minutes of uracil addition and peaks within 30 minutes. Similarly, transcription rapidly drops after transfer to medium without uracil. (Watt et al, 2008)

• T adh1-tetO2: It is composed of two parts. The first one is the ADH1 terminator, which functions as an insulator or boundary for transcription isolation. The second one is formed by two tetR operator sequences (tetO2), of 19 nucleotides each one, alternated with spacers. This composite part should be inserted just in front of a promoter, in order to control its regulations by generating a nucleated structure of heterochromatinic DNA, together with his associated part tetO4-terminator. Compaction of DNA is due to binding of engineered silencing proteins (tetR+heterochromatin forming protein)to tetO sequences.

• GFP-Tadh1- tetO4- Tact1:This composite part is formed by four main elements: GFP, adh1 terminator, tetO4 and act1 terminator. Coding sequence of GFP reporter protein is followed by the transcriptional terminator of ADH1 gene. The next part is denominated tetO4, that consist of four 19 nucleotices tetR operator sequences, alternated with spacers. And the last part is the Act1 transcriptional terminator that function as insulator. This part should be interted behind a promoter. In association with Tadh1-tetO2 part, it functions as a transcription regulator, by compacting intermediate sequence.

• TetR-CSD:It is composed by tetracycline repressor and the chromoshadow domain of Swi6. TetR is responsible of binding to tetR operator sites, flanking reporter marker. CSD is a protein-protein interaction domain that contains a dimerization motif that creates a cleft, mediating compaction of reporter module. (Cowieson et al, 2000; Haldar et al, 2011)

• Swi6, SP, critical protein for heterochromatin assembly in fission yeast, involved in stabilization of heterochromatin structure, because it contains a chromodomain (CD) and a chromoshadow domain (CSD). The property of Swi6 to form multimers is thought to cause folding of chromatin into a transcriptionally inactive structure. (Bühler & Gasser, 2009; Cowieson et al, 2000; Haldar et al, 2011)