mechanizm sekrecji i translokacji Yop proteins of Yersinia species

mechanizm sekrecji i translokacji Yop proteins of Yersinia species

POST. MIKROBIOL.,
1999, 38, 2, 141-162
BIAŁKA YOP RODZAJU YERSINIA
- MECHANIZM SEKRECJI I TRANSLOKACJI
Adrianna Górka, Katarzyna Brzostek, Jerzy Hrebenda
1. Wprowadzenie. 2. Sekrecja białek u bakterii Gram-ujemnych. 2.1. III typ sekrecji. 2.2. Białka Yop.
3. Mechanizm sekrecji. 3.1. Sygnały sekrecyjne. 3.2. Białka Ysc budujące aparat sekrecyjny.
3.3. Cytoplazmatyczne białka opiekuńcze Syc. 4. Mechanizmy translokacji białek Yop. 4.1. Białka
uczestniczące w translokacji. 5. Kontrola procesu uwalniania białek wirulencji. 5.1. Rola białek
YopN, TyeA i LcrG. 6. Kontrola procesu syntezy białek Yop. 6.1. Kontrola temperaturowa.
6.1. Regulacja wapniowa. 7. Uwagi końcowe
Yop proteins of Yersinia species - the mechanisms of secretion and translocation
Abstract:
Pathogenic yersiniae secrete about a dozen anti-host proteins, the Yops, by a
pathway which does not involve cleavage of a classical signal peptide. The Yop secretory
apparatus, called Ysc is the archetype of type III secretion systems which serves for the
secretion of virulence proteins by several animal and plant pathogens. This designation was
proposed to distinguish it from „type I” and „type II” pathways. The Yops form two distinct
groups of proteins. The first group includes intracellular effector proteins that are injected
into eukaryotic cells by extracellular Yersinia adhering at the cell surface. The second group
is involved in tranlocation of the effectors across the eukaryotic cell membrane. This allows
extracellular bacteria to deliver toxic Yop proteins inside the host cell cytosol in order to
interfere with signal transdution and attack host cell cytoskeleton. The Yops and secretion
apparatus are encoded by a 7Okb plasmid called pYV. The ysc genes are contained in four
loci called virA, virB, virG and virC in Y. enterocolitica. At least 28 proteins build a complex
secretion machinery.
1. Introduction. 2. Secretion of proteins in Gram-negative bacteria. 2.1. III type of secretion. 2.2. Yop
proteins. 3. Mechanism of secretion. 3.1. Secretion signals. 3.2. Ysc secretion apparatus. 3.3. Syc
cytosolic chaperones. 4. Mechanisms of Yops translocation. 4.1. Proteins participating in
translocation. 5. Control of delivery of virulence proteins. 5.1. Role of YopN, TyeA and LcrG.
6. Control of Yops synthesis. 6.1. Temperature control. 6.2. Calcium regulation. 7. Concluding
remarks