Inadive Condition Active Condition Example 21.3 There are many Protein synthesized types of DNA-binding No protein 中 Homeoproteins Protein phosphorylated domains 八风凡 八NN八N HSTF Inactive prot Protein dephosphoryated NN个 八八八N入 Figure 21.2 The activity of a Inactive protein Ligand binding regulatory transcription 八MN八八N ny factor may be controlled by Inactive prot synthesis of protein, Cleavage to release adive factor covalent modification of 八凡八八N 八入八代风 Sterol protein,ligand binding,or response Membrane-bound protein Release byinhibitor binding of inhibitors that NM八八八N 八八N sequester the protein or Inactive prot NF-kB affect its ability to bind to Inhibitor Change of partner DNA. 八NNN Inactive prot → 品DAD) 情菜大当 Inactive partner
Figure 21.2 The activity of a regulatory transcription factor may be controlled by synthesis of protein, covalent modification of protein, ligand binding, or binding of inhibitors that sequester the protein or affect its ability to bind to DNA. 21.3 There are many types of DNA-binding domains
21.3 There are Mechanism of factor many types of DNA- 1-k8 Jun Fos p65-p50 dimer binding domains NFk短 风风入入N N八NM风MW AP-1 may be Ligand binding acivates thyroid hormone receptor requlated by (as dimer with RXR) Phosphorylation of phosphorylation -kB releases NF-k日 Figure 28.19 Oncogenes As that code for transcription factors have mutations that VV inactivate transcription Function of oncogenic factor (v-erbA and possibly v- v-Rel has lost regions needed to stay in cytoplasm V-E rbA has lo过 v-Jun y-Fos have temminal TH-pinding ate rel)or that activate truncations and point mutations 八NNN transcription (v-jun and M八八N v-fos). v-Rel may prevent p65/p50 fom y-Jun and v-Fos may activate target v-ErbA cannot activate forming dimer and/or adtivating genes without responding to usual transcription,and also inhibits transcription controls 清菜大兰
Figure 28.19 Oncogenes that code for transcription factors have mutations that inactivate transcription (v-erbA and possibly vrel) or that activate transcription (v-jun and v-fos). 21.3 There are many types of DNAbinding domains
21.4 A zinc finger motif is a DNA-binding domain Figure 21.3 Transcription factor SPI has a series of three zinc fingers,each with a characteristic pattern of cysteine and histidine residues that constitute the zinc-binding site 清菜大当
Figure 21.3 Transcription factor SP1 has a series of three zinc fingers, each with a characteristic pattern of cysteine and histidine residues that constitute the zinc-binding site. 21.4 A zinc finger motif is a DNA-binding domain
21.4 A zinc finger motif is a DNA-binding domain Figure 21.4 Zinc 000 fingers may form a-helices that Foms Forms B-sheeto-helix insert into the major groove, associated with B- sheets on the other side. 清第大当
Figure 21.4 Zinc fingers may form a-helices that insert into the major groove, associated with bsheets on the other side. 21.4 A zinc finger motif is a DNA-binding domain
21.4 A zinc finger motif is a 0 DNA-binding domain 8 8 9000000 0000 Figure 21.5 The first finger of a DNA binding Dimerization steroid receptor controls specificity of DNA-binding (positions shown in red);the second finger controls specificity of dimerization(positions shown in blue).The expanded view of 8 the first finger shows that 090.。 discrimination between GRE and 6@→@ Glucocorticoid Estrogen ERE target sequences rests on specificity specificity two amino acids at the base. Same sequence in both receptors Different sequence in each receptor 情華大当
Figure 21.5 The first finger of a steroid receptor controls specificity of DNA-binding (positions shown in red); the second finger controls specificity of dimerization (positions shown in blue). The expanded view of the first finger shows that discrimination between GRE and ERE target sequences rests on two amino acids at the base. 21.4 A zinc finger motif is a DNA-binding domain