Proteolityczny kombinat i jego regulatory
Journal Title: Wiadomości Chemiczne - Year 2012, Vol 66, Issue 11
Abstract
One of the proteolytic pathways existing in a cell is ubiquitin- proteasome system (UPS). This highly organized and ATP-dependent system is based on the multifunctional enzyme – the proteasome. Ubiquitin in this pathway plays a role of a tag which marks proteins intended for destruction. Ubiquitylated proteins are recognized and degraded by the 26S proteasome. It consists of a cylindrical-shaped proteolytic core – the proteasome 20S, and attached to it regulatory particles 19S (Fig. 2). The core is composed of four rings, each of them formed by seven subunits. The inner â-rings harbour active sites (in Eukaryota two of each kind: chymotrypsin-like (ChT-L), trypsin-like (T-L) and peptidylglutamyl (PGPH)). The outer, á-rings create a gated channel leading to the catalytic chamber [8]. In a latent proteasome the gate is closed by tightly packed N-terminal residues of á subunits (Fig. 4). Due to such architecture the active sites of the proteasome are not freely available for the substrates. An opening of the gate in physiological conditions occurs after binding the activators such as 11S, 19S or PA200. By catalysing degradation of proteins, the UPS is deeply involved in regulation of cellular physiology. It is also involved in removing of misfolded or damaged proteins and supports the immune system by generating antigenic peptides. Defects in functioning of this proteolytic system play a causal role in the development of a number of diseases, including inflammation, neurodegenerative diseases and various cancers [2–6] what is the reason why the proteasome has become an important therapeutic target. Detailed information about the structure, catalytic activities and mechanisms of functioning of the different proteasome complexes existing in cells is essential to understand their role in organisms as well as to develop new compounds which may find pharmaceutical application.
Authors and Affiliations
Julia Stój, Przemysław Karpowicz
Keywords
Related Articles
- EP ID EP590251
- DOI -
- Views 132
- Downloads 0
Adenozyno-5’-o-(n-acylosulfamoilowe) pochodne jako potencjalne leki przeciwgruźlicze
Mycobacterium tuberculosis (Mtb), the etiological agent of tuberculosis (TB), is the leading bacterial cause of infectious disease mortality. The current WHOapproved treatment for TB involves a three- or four-drug regime...
Sieci metalo-organiczne jako multifunkcjonalne materiały przyszłości : mechanochemiczne podejście do syntezy
Metal-organic frameworks (MOFs) are a relatively new class of advanced inorganic-organic materials. Due to their modular structures and possible incorporation of various properties, that materials find more and more appl...
Efekt kooperatywności oddziaływań iekowalencyjnych w wybranych układach molekularnych stabilizowanych wiązaniami wodorowymi i halogenowymi
Among various so-called weak interactions, a halogen bond [8 and references therein] is currently probably one of more explored by researchers. This is due to the fact that it has several properties in common with the hy...
Wpływ heterogeniczności powierzchni biokoloidów na ich rozdzielanie elektroforetyczne
Electrical properties of biocolloids, due to the unique structure and properties of the walls and cell membranes are altered by ions present in the environment. This change in the surface properties of bacterial cells ha...
Otrzymywanie i właściwości adsorpcyjne sieci metaloorganicznych
MOF materials or metal-organic frameworks are compounds consisting of metal ions or clusters (metal junctions) and organic ligands (bridging groups) connected via coordination bonds. Since a variety of organic ligands an...