Reverse-phase phosphoproteome analysis of signaling pathways induced by Rift valley fever virus in human small airway epithelial cells.
Rift valley fever virus (RVFV) infection is an emerging zoonotic disease endemic in many countries of sub-Saharan Africa and in Egypt. In this study we show that human small airway epithelial cells are highly susceptible to RVFV virulent strain ZH-501 and the attenuated strain MP-12. We used the reverse-phase protein arrays technology to identify phosphoprotein signaling pathways modulated during infection of cultured airway epithelium. ZH-501 infection induced activation of MAP kinases (p38, JNK and ERK) and downstream transcriptional factors [STAT1 (Y701), ATF2 (T69/71), MSK1 (S360) and CREB (S133)]. NF-κB phosphorylation was also increased. Activation of p53 (S15, S46) correlated with the increased levels of cleaved effector caspase-3, -6 and -7, indicating activation of the extrinsic apoptotic pathway. RVFV infection downregulated phosphorylation of a major anti-apoptotic regulator of survival pathways, AKT (S473), along with phosphorylation of FOX 01/03 (T24/31) which controls cell cycle arrest downstream from AKT. Consistent with this, the level of apoptosis inhibitor XIAP was decreased. However, the intrinsic apoptotic pathway marker, caspase-9, demonstrated only a marginal activation accompanied by an increased level of the inhibitor of apoptosome formation, HSP27. Concentration of the autophagy marker, LC3B, which often accompanies the pro-survival signaling, was decreased. Cumulatively, our analysis of RVFV infection in lung epithelium indicated a viral strategy directed toward the control of cell apoptosis through a number of transcriptional factors. Analyses of MP-12 titers in challenged cells in the presence of MAPK inhibitors indicated that activation of p38 represents a protective cell response while ERK activation controls viral replication.
National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia, United States of America.
Taissia G
TG
Popova
Michael J
MJ
Turell
Virginia
V
Espina
Kylene
K
Kehn-Hall
Jessica
J
Kidd
Aarthi
A
Narayanan
Lance
L
Liotta
Emanuel F
EF
Petricoin
Fatah
F
Kashanchi
Charles
C
Bailey
Serguei G
SG
Popov
D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D004847:Epithelial Cells / Q000378:metabolism* / Q000821:virology*; D005260:Female; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis* / Q000378:metabolism; D020543:Proteome / Q000032:analysis* / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D012137:Respiratory System / Q000166:cytology; D012295:Rift Valley Fever / Q000821:virology; D012296:Rift Valley fever virus / Q000302:isolation & purification / Q000502:physiology*; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism; D051636:X-Linked Inhibitor of Apoptosis Protein / Q000378:metabolism
D055551:HSP27 Heat-Shock Proteins; D010750:Phosphoproteins; D020543:Proteome; D014157:Transcription Factors; D051636:X-Linked Inhibitor of Apoptosis Protein; C496866:XIAP protein, human; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; D020169:Caspases