The ubiquitin C-terminal hydrolase UCH-L1 promotes bacterial invasion by altering the dynamics of the actin cytoskeleton

TY - JOUR

T1 - The ubiquitin C-terminal hydrolase UCH-L1 promotes bacterial invasion by altering the dynamics of the actin cytoskeleton

AU - Bassères, Eugénie

AU - Coppotelli, Giuseppe

AU - Pfirrmann, Thorsten

AU - Andersen, Jens Bo

AU - Masucci, Maria

AU - Frisan, Teresa

N1 - © 2010 Blackwell Publishing Ltd.

PY - 2010/11

Y1 - 2010/11

N2 - Invasion of eukaryotic target cells by pathogenic bacteria requires extensive remodelling of the membrane and actin cytoskeleton. Here we show that the remodelling process is regulated by the ubiquitin C-terminal hydrolase UCH-L1 that promotes the invasion of epithelial cells by Listeria monocytogenes and Salmonella enterica. Knockdown of UCH-L1 reduced the uptake of both bacteria, while expression of the catalytically active enzyme promoted efficient internalization in the UCH-L1-negative HeLa cell line. The entry of L. monocytogenes involves binding to the receptor tyrosine kinase Met, which leads to receptor phosphorylation and ubiquitination. UCH-L1 controls the early membrane-associated events of this triggering cascade since knockdown was associated with altered phosphorylation of the c-cbl docking site on Tyr1003, reduced ubiquitination of the receptor and altered activation of downstream ERK1/2- and AKT-dependent signalling in response to the natural ligand Hepatocyte Growth Factor (HGF). The regulation of cytoskeleton dynamics was further confirmed by the induction of actin stress fibres in HeLa expressing the active enzyme but not the catalytic mutant UCH-L1(C90S) . These findings highlight a previously unrecognized involvement of the ubiquitin cycle in bacterial entry. UCH-L1 is highly expressed in malignant cells that may therefore be particularly susceptible to invasion by bacteria-based drug delivery systems.

AB - Invasion of eukaryotic target cells by pathogenic bacteria requires extensive remodelling of the membrane and actin cytoskeleton. Here we show that the remodelling process is regulated by the ubiquitin C-terminal hydrolase UCH-L1 that promotes the invasion of epithelial cells by Listeria monocytogenes and Salmonella enterica. Knockdown of UCH-L1 reduced the uptake of both bacteria, while expression of the catalytically active enzyme promoted efficient internalization in the UCH-L1-negative HeLa cell line. The entry of L. monocytogenes involves binding to the receptor tyrosine kinase Met, which leads to receptor phosphorylation and ubiquitination. UCH-L1 controls the early membrane-associated events of this triggering cascade since knockdown was associated with altered phosphorylation of the c-cbl docking site on Tyr1003, reduced ubiquitination of the receptor and altered activation of downstream ERK1/2- and AKT-dependent signalling in response to the natural ligand Hepatocyte Growth Factor (HGF). The regulation of cytoskeleton dynamics was further confirmed by the induction of actin stress fibres in HeLa expressing the active enzyme but not the catalytic mutant UCH-L1(C90S) . These findings highlight a previously unrecognized involvement of the ubiquitin cycle in bacterial entry. UCH-L1 is highly expressed in malignant cells that may therefore be particularly susceptible to invasion by bacteria-based drug delivery systems.

KW - Actins

KW - Blotting, Western

KW - Cell Line, Tumor

KW - Cell Membrane

KW - Cytoskeleton

KW - Epithelial Cells

KW - Gene Knockdown Techniques

KW - HeLa Cells

KW - Hepatocyte Growth Factor

KW - Humans

KW - Listeria monocytogenes

KW - Mitogen-Activated Protein Kinase 1

KW - Mitogen-Activated Protein Kinase 3

KW - Phosphorylation

KW - Proto-Oncogene Proteins c-akt

KW - Proto-Oncogene Proteins c-cbl

KW - Salmonella enterica

KW - Signal Transduction

KW - Ubiquitin Thiolesterase

KW - Ubiquitination

U2 - 10.1111/j.1462-5822.2010.01495.x

DO - 10.1111/j.1462-5822.2010.01495.x

M3 - Journal article

C2 - 20608941

SN - 1462-5822

VL - 12

SP - 1622

EP - 1633

JO - Cellular Microbiology Online

JF - Cellular Microbiology Online

IS - 11

ER -