Loopy expression

Yeast is unusual in that its transcriptional activators cannot work over long distances. But in the 4 January Nature, de Bruin et al. report that the looping of heterochromatic-like telomere regions corrects this shortcoming (Nature 2001, 409:109-113). They place a binding site for the activator Gal4 downstream of a reporter gene. The site is inactive when the reporter is at an internal chromosomal locus, but active when the gene cassette is placed, in either orientation, near the telomere. Only

By | January 8, 2001

Yeast is unusual in that its transcriptional activators cannot work over long distances. But in the 4 January Nature, de Bruin et al. report that the looping of heterochromatic-like telomere regions corrects this shortcoming (Nature 2001, 409:109-113). They place a binding site for the activator Gal4 downstream of a reporter gene. The site is inactive when the reporter is at an internal chromosomal locus, but active when the gene cassette is placed, in either orientation, near the telomere. Only at the telomere is Gal4 associated with promoter DNA, as assayed by chromatin immunoprecipitation. This leads de Bruin et al. to suggest that telomere looping brings the activator close to the promoter to activate transcription. Such looping may be impossible elsewhere in the yeast genome because yeast lacks either the heterochromatic regions or auxiliary looping proteins present in other species.

Popular Now

  1. Running on Empty
    Features Running on Empty

    Regularly taking breaks from eating—for hours or days—can trigger changes both expected, such as in metabolic dynamics and inflammation, and surprising, as in immune system function and cancer progression.

  2. Athletes’ Microbiomes Differ from Nonathletes
  3. Mutation Linked to Longer Life Span in Men
  4. Gut Feeling
    Daily News Gut Feeling

    Sensory cells of the mouse intestine let the brain know if certain compounds are present by speaking directly to gut neurons via serotonin.

AAAS