Paralytic activity of lysophosphatidylcholine from saliva of the waterbug Belostoma anurum.
Lysophosphatidylcholine (LPC) is a major bioactive lipid that is enzymatically generated by phospholipase A(2) (PLA(2)). Previously, we showed that LPC is present in the saliva of the blood-sucking hemipteran Rhodnius prolixus and modulates cell-signaling pathways involved in vascular biology, which aids blood feeding. Here, we show that the saliva of the predator insect Belostoma anurum contains a large number of lipids with LPC accounting for 25% of the total phospholipids. A PLA(2) enzyme likely to be involved in LPC generation was characterized. The activity of this enzyme is 5-fold higher in Belostoma saliva than in other studied hemipterans, suggesting a close association with the predator feeding habits of this insect. Belostoma employs extra-oral digestion, which allows for ingestion of larger prey than itself, including small vertebrates such as amphibians and fish. Therefore, prey immobilization during digestion is essential, and we show here that Belostoma saliva and B. anurum saliva purified LPC have paralytic activity in zebrafish. This is the first evidence that lysophospholipids might play an important role in prey immobilization, in addition to contributing to blood feeding, and might have been an evolutionary acquisition that occurred long before the appearance of hematophagy in this animal group.
Silva-Cardoso
Lívia
L
Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, PO Box 68041, Cidade Universitária, Ilha do Fundão, Av. Bauhínia 400, Rio de Janeiro, CEP 21941-590, RJ, Brazil.
Caccin
Paola
P
Magnabosco
Anna
A
Patrón
Maria
M
Targino
Mariane
M
Fuly
André
A
Oliveira
Giselle A
GA
Pereira
Marcos H
MH
do Carmo
Maria das Graças T
Md
Souza
Amanda S
AS
Silva-Neto
Mário A C
MA
Montecucco
Cesare
C
Atella
Georgia C
GC
D000818:Animals; D002478:Cells, Cultured; D020062:Heteroptera / Q000378:metabolism* / Q000472:pathogenicity*; D007103:Immobilization; D066298:In Vitro Techniques; D008244:Lysophosphatidylcholines / Q000378:metabolism* / Q000633:toxicity*; D051379:Mice; D009474:Neurons / Q000187:drug effects; D010243:Paralysis / Q000139:chemically induced; D054467:Phospholipases A2 / Q000378:metabolism; D010791:Phrenic Nerve / Q000187:drug effects; D011235:Predatory Behavior / Q000502:physiology*; D051381:Rats; D012463:Saliva / Q000378:metabolism; D013045:Species Specificity; D015027:Zebrafish
D008244:Lysophosphatidylcholines; D054467:Phospholipases A2