from PART I - PHYSIOLOGY
Published online by Cambridge University Press: 10 May 2010
Introduction
For more than 30 years, the inositol phospholipids and the activities of various phospholipases have been intimately associated with fundamental aspects of the stimulation of platelets. Works of various scientific groups led to the initial discoveries in the 1970s and 1980s that related the metabolism of phospholipids to the early platelet physiological responses such as shape change, secretion, and aggregation. In many instances, these findings were used to develop signal transduction concepts in many other biological systems. The products resulting from activation of these phospholipases represent myriad second messengers with relevant biological roles. Phospholipases and their substrates and products are central to the action of many receptors, transducers, and protein kinases, as well as to the mobilization of ions. This chapter describes the roles of phospholipase C and phospholipase D in signal transduction, and it discusses how these activities interplay in a network of pathways leading to physiological responses.
Overview of phospholipase C
Phosphoinositide-specific phospholipase C (PLC) plays an essential role in receptor-mediated platelet activation. The mammalian PLCs represent a family of Ca2+-dependent enzymes showing a substrate preference for phosphatidylinositol 4, 5-bisphosphate (PIP2) over phosphatidylinositol 4-phosphate (PIP) or phosphatidylinositol (PI). Hydrolysis of PIP2 by PLC leads to the generation of two important intracellular messengers: inositol 1, 4, 5-trisphosphate (IP3) and diacylglycerol (DAG). IP3 is a soluble molecule that promotes the rapid release of Ca2+ from internal stores.
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.