LIFESCI 3 Lecture Notes - Lecture 26: Sticky And Blunt Ends, Drosha, Allosteric Regulation
Document Summary
Lecture 26 recap gal: multiple layers of signaling, default state: gal 4 and gal 80 expressed constitutively. Gal 4 binds upstream activation sequences for gal1 gene; activation domain interacts with rna pol & general transcription factors. Gal 4 co-expressed with gal 80 (co-repressor, no direct binding with dna) Gal 80 blocks activation domain of gal 4. Gal3 in cytoplasm binds to lactose -> change in shape & enter nucleus -> joins gal4 & gal80 -> (cid:396)e(cid:448)eal gal(cid:1008)"s a(cid:272)ti(cid:448)atio(cid:374) do(cid:373)ai(cid:374) -> gal4 stimulates transcription with general transcription factors. Complex of gal4, 3, 80 recruit saga & swi/snf (hat) (all 3 of them have to be present) If gal4 absent -> no expression at all. If gal80 absent -> constant gal1 expression gene (only if entire gene is untraveled) Imprinting: ge(cid:374)de(cid:396) of pa(cid:396)e(cid:374)tal (cid:272)h(cid:396)o(cid:373)oso(cid:373)e dete(cid:396)(cid:373)i(cid:374)es if the(cid:396)e"s ge(cid:374)e e(cid:454)p(cid:396)essio(cid:374) Insulator bound by repressor between enhancer and promoter: repressor is large -> interferes with dna binding that gets activation signal pulsed to promoter.
