Abstract
The family Baculoviridae harbours a large number of invertebrate viruses, mainly infecting caterpillars of the order Lepidoptera. The
baculovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) causes several alterations in its host S. exigua, including
physiological and behavioural changes, as well as immunological responses (apoptosis in hemocytes). It is likely that these changes in the
host underlie efficient virus transmission. Here we show that the viral encoded protein tyrosine phosphatase 2 (PTP2) induces apoptosis
in Spodoptera frugiperda (Sf ) 21 cells upon transient expression. Transfection with a catalytic site mutant did not lead to apoptosis,
indicating that the phosphatase activity of PTP2 was needed to induce apoptosis. We also found that the caspase level (indicator of
apoptosis) was higher in cells transfected with the ptp2 gene than in cells transfected with the ptp2 catalytic mutant. A caspase inhibitor
reduced the level of ptp2-induced apoptosis. PTP2 shares a functional domain with mitogen-activated protein kinase (MAPK) phosphatases
(MKPs), which are important cellular proteins that regulate many cellular processes, including apoptosis and other immune responses. The
phylogenetic relation between PTP2 and insect MPKs further suggests that PTP2 might have MPK activity. Overall, we hypothesize that
SeMNPV PTP2 functions as a MKP and possibly induces apoptosis specifically in hemocytes to suppress immune responses. We are currently
performing proteomic studies to determine which MAPK may serve as a substrate for PTP2.
baculovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) causes several alterations in its host S. exigua, including
physiological and behavioural changes, as well as immunological responses (apoptosis in hemocytes). It is likely that these changes in the
host underlie efficient virus transmission. Here we show that the viral encoded protein tyrosine phosphatase 2 (PTP2) induces apoptosis
in Spodoptera frugiperda (Sf ) 21 cells upon transient expression. Transfection with a catalytic site mutant did not lead to apoptosis,
indicating that the phosphatase activity of PTP2 was needed to induce apoptosis. We also found that the caspase level (indicator of
apoptosis) was higher in cells transfected with the ptp2 gene than in cells transfected with the ptp2 catalytic mutant. A caspase inhibitor
reduced the level of ptp2-induced apoptosis. PTP2 shares a functional domain with mitogen-activated protein kinase (MAPK) phosphatases
(MKPs), which are important cellular proteins that regulate many cellular processes, including apoptosis and other immune responses. The
phylogenetic relation between PTP2 and insect MPKs further suggests that PTP2 might have MPK activity. Overall, we hypothesize that
SeMNPV PTP2 functions as a MKP and possibly induces apoptosis specifically in hemocytes to suppress immune responses. We are currently
performing proteomic studies to determine which MAPK may serve as a substrate for PTP2.
| Original language | English |
|---|---|
| Publication status | Published - Jul 2016 |
| Event | SIP 2016 Tours: the International Congress on Invertebrate Pathology and Microbial Control and the 49th Annual Meeting of the Society for Invertebrate Pathology - Tours, Tours, France Duration: 24 Jul 2016 → 28 Jul 2016 http://sip2016tours.org/ |
Conference
| Conference | SIP 2016 Tours |
|---|---|
| Abbreviated title | SIP |
| Country/Territory | France |
| City | Tours |
| Period | 24/07/16 → 28/07/16 |
| Internet address |