14.1 Transient Changes in Genome activity Most cells in multicellular organisms live in less variable environments but the maintenance of this environment requires coordination between the activities of different cells To exert an effect on genome activity, the nutrient, hormone, growth factor, or other extracellular compound that represents the external stimulus must influence events within the cell
14.1 Transient Changes in Genome Activity • Most cells in multicellular organisms live in less variable environments, but the maintenance of this environment requires coordination between the activities of different cells. • To exert an effect on genome activity, the nutrient, hormone, growth factor, or other extracellular compound that represents the external stimulus must influence events within the cell
Direct activation Indirect activation signaling compound signal transduction enters the cell via a cell surface receptor Surface receptor ODD
14.1.1 Signal transmission by import of the extracellular signaling compound Signaling compound directly influences a protein factor Signaling com- pound is an activator o→ Genome repressor of transcription ⑩D Signaling compound indirectly influences a protein factor
14.1.1 Signal transmission by import of the extracellular signaling compound
Lactoferrin is an extracellular signaling protein Which acts as a transcription activator not a common mechanism difficulty in designing a protein that combines the hydrophobic properties needed for effective transport across a membrane with the hydrophilic properties needed for migration through the aqueous cytoplasm to the protein's site of action in the nucleus or on a ribosome.想想大宝SOD蜜的护肤机理 Lactoferrin play a role in the body's defenses against microbial attack, by reducing free-iron levels in milk, thereby starving invading microbes of this essential cofactor Its dna binding was shown to be sequence specific and to stimulate transcription, confirming that lactoferrin is a true transcription activator
Lactoferrin is an extracellular signaling protein which acts as a transcription activator • not a common mechanism • difficulty in designing a protein that combines the hydrophobic properties needed for effective transport across a membrane with the hydrophilic properties needed for migration through the aqueous cytoplasm to the protein‘s site of action in the nucleus or on a ribosome. 想想大宝SOD蜜的护肤机理。 • Lactoferrin: play a role in the body's defenses against microbial attack, by reducing free-iron levels in milk, thereby starving invading microbes of this essential cofactor. • Its DNA binding was shown to be sequence specific and to stimulate transcription, confirming that lactoferrin is a true transcription activator
Some imported signaling compounds directly influence the activity of pre-existing protein factors Environmental concentration of copper Lactose Nutritional Toxic copper and zinc Cu CuCucu Steroid hormones Cu CuCucu Cu Cu Cu Cu Cu Cu Cu Estrogen receptor C Cu Cu Progesterone receptor N Active Mac1p Active Acelp Glucocorticoid receptor CTR1 CUPT N sC CTR3 CRS5 200 amino ac FRET SOD1 KEY a Variable region DNA-binding domain Synthesis of copper- Synthesis of copper Hormone-binding domain uptake proteins detoxification proteins
Some imported signaling compounds directly influence the activity of pre-existing protein factors Lactose copper and zinc Steroid hormones