The proteolytic enzymes have an essential function in all cells. Their activities are regulated by the rate of synthesis, activation of proenzymes and by the rate of synthesis of their inhibitors. They are synthesized in ribosomes like any other proteins and transported to various storage organelles or secreted from the cells and are activated in the pericellular space or in interstitium. Various cells and tissues have their characteristic enzyme patterns which serve their specific functions. Proteolytic enzymes take part and often have a regulatory role in numerous phases of cell function, e.g. cell division, migration, apoptotic as well as necrotic cell death etc. Diseases in which proteolysis has been subject of active research are e.g. cancer metastasis, viral infections, e.g. HIV, and Alzheimer's disease. They are also an essential part in any tissue remodelling, wound healing, throughout the kingdom of fauna and flora.

Proteolysis by the ubiquitin-proteasome pathway (UPP) in the nervous system has been extensively studied both in the context of normal physiological function as well as abnormal pathological conditions. Although ubiquitin was used as a marker of brain pathology, the normal functions of the UPP were not studied much in the nervous system until the 1990s. The early investigations focused on synaptic plasticity which was followed by studies on the roles of protein degradation in the development of the nervous system. Research on the role of abnormal roles of the UPP follows a parallel trajectory. Since the 2000s, the field has grown to encompass many subareas of research and several model systems. Despite the progress made, many unanswered questions still remain. For example, there are many unknowns about the precise spatial and temporal control of protein degradation in the normal nervous system. With respect to the roles of proteolysis in brain pathology a major challenge is to elucidate the connection between impaired protein degradation and disease progression. In addition, in-depth studies of the roles of ubiquitin-proteasome-mediated proteolysis in neurodegenerative diseases are promising in identifying therapeutic targets. This ebook contains original research papers and insightful reviews that cover several aspects of proteolysis by the UPP and its physiological as well as pathological functions in the nervous system.

This book contains an extensive collection of critical reviews, from leading researchers in the field of regulated protein degradation. It covers the role of regulated proteolysis in a range of microorganisms (from Gram positive, Gram negative and pathogenic bacteria to Archaea and the Baker’s yeast Saccharomyces cerevisiae).

Intracellular Calcium-Dependent Proteolysis explains what is now known about calpains, which are intracellular, non-lysosomal enzymes involved in intracellular protein catabolism. The book provides a comprehensive overview of topics ranging from the molecular biology of the calpains and their specific inhibitor protein (calpastatin) to physiologic and pathologic consequences of the presence of this proteolytic system in many model cells and tissues. Several theoretical functions of the calpains are discussed, including their potential roles in muscle protein turnover, platelet activation, membrane fusion, and synaptic plasticity. Intracellular Calcium-Dependent Proteolysis is a valuable source of information for researchers and students interested in the regulation of intracellular protein catabolism and the general effects of Ca2+ on cell function.

This book highlights proteasome structures and how they are related to different aspects of proteasome function. Moreover, the book reports on the functional roles these highly developed proteolytic machines play within the cell. It was a great surprise to the scientific world that proteolysis provides crucial functions in cellular regulation. The

Proteins are considered supremely important for the organization, survival, and functioning of living organisms. They were considered stable and static molecules until the early 1940s, when RudolphSchoenheimer demonstrated that proteins exist in a constant dynamic process of synthesis and degradation (proteostasis), absolutely essential for life. Since then, general and limited protein degradation became some of the most fascinating aspects of biological sciences. This book is focused on a particular aspect of protein degradation, namely, limited proteolysis, which gives rise to bioactive peptides as a result of the enzymatic action of proteinases and peptidases, which are enzymes that hydrolyze specific peptide bonds of proteins and peptides, respectively. In a broad sense, bioactive peptides are any fragment of endogenous or exogenous proteins able to elicit either physiological or pathological activities. Here, we aim at presenting to the readers that bioactive peptides are not merely produced through random processes during protein degradation, but rather through a well-organized enzymatic process that is deeply integrated in the homeostatic processes of living organisms.

Proteostasis integrates biological pathways controlling biogenesis, trafficking, folding, and degradation of proteins. This book focuses on two protein breakdown/degradation processes (proteolysis), which are part of a normally functioning proteostatic system: the ubiquitin-proteasome system and autophagy. Chapter 2 of this book is freely available as a downloadable Open Access PDF at http://www.taylorfrancis.com under a Creative Commons Attribution-Non Commercial-No Derivatives (CC-BY-NC-ND) 4.0 license.

Completely revised and updated to incorporate the latest data in the field, Lewin's CELLS, Second Edition is the ideal resource for advanced undergraduate and graduate students entering the world of cell biology. Redesigned to incorporate new learning tools and elements, this edition continues to provide readers with current coverage of the structure, organization, growth, regulation, movements, and interaction of cells, with an emphasis on eukaryotic cells. Under the direction of three expert lead editors, new chapters on metabolism and general molecular biology have been added by subject specialist. All chapters have been carefully edited to maintain consistent use of terminology and to achieve a homogenous level of detail and rigor. A new design incorporates many new pedagogical elements, including Concept & Reasoning Questions, Methods boxes, Clinical Applications boxes, and more.