Chapter 2, Problem 30E

Summary Introduction

Introduction:

While there are several proteins that are synthesized via several pathways, their degradation is also a very important part and as necessary as synthesis is. There is a number of factors that lead to the degradation of proteins. Some proteins are degraded in response to some signal to take part in the mechanism of intracellular enzyme activities. Some undergo degradation so as to function as regulatory molecules. Also, there are some faulty or damaged proteins which are recognized and degraded within the cells.

The differential rate of protein degradation is an important aspect o cell regulation.

Two major pathways by which protein degradation is mediated, in eukaryotic cells, are:

• the ubiquitin-proteasome pathway
• the lysosomal pathway.