国外大学细胞生物学课件 英文课件14.ppt

D103 - Cell Biology - lecture 14 ? 2011 Grant MacGregor & Christine S ü tterlin – All rights reserved Page 1 ? Signaling is vital to both uni- and multi-anisms. ? During evolution, signaling systems have evolved mon simple beginnings to e sophisticated, overlapping and integrated processes. ? Staying sane while learning about signaling – identifying conserved principles and ponents in different pathways. ? Principles, part I ? Overview of a generic signaling pathway. ? Types of signals; Properties of a good signal. ? Conformational change – mon way to regulate protein activity. ? Non-covalent binding of atoms and molecules can regulate a protein ’ s activity. ? Covalent modification is mon method to regulate protein activity. ? Changes in molecular structure affect specificity of molecular interactions. Lecture 14 - Signaling I : Introduction to signaling mended Reading: MBOC 5e, pages 124 - 158 D103 - Cell Biology - lecture 14 ? 2011 Grant MacGregor & Christine S ü tterlin – All rights reserved Page 2 What is signaling and why is it needed ? ? The plasma membrane forms a barrier between the inside of a cell and its extra- cellular environment .? Cells require a method to sense their extra-cellular (and intra-cellular !) environments .? Signaling allows a cell to receive information from its external environment and to respond to the signal . prokaryotic cell eukaryotic cell D103 - Cell Biology - lecture 14 ? 2011 Grant MacGregor & Christine S ü tterlin – All rights reserved Page 3 What is signaling and why is it needed ? ? anisms use signaling for many reasons involving environmental conditions; . sensing nutrient supply , osmotic stress , the presence of a mate ! ? Metazoan organisms use signaling for same reasons , as well as to co-ordinate proper control of development and homeostasis . ? Every anism uses similar types of signaling that evolved from early anisms . All anisms likely