PHOSPHORYLATION OF COCKROACH ANTENNAL POLYPEPTIDES - EFFECTS OF 2ND MESSENGERS AND PHEROMONAL BLEND

Citation
M. Renucci et al., PHOSPHORYLATION OF COCKROACH ANTENNAL POLYPEPTIDES - EFFECTS OF 2ND MESSENGERS AND PHEROMONAL BLEND, Experientia, 52(8), 1996, pp. 762-768
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary Sciences
Journal title
ISSN journal
0014-4754
Volume
52
Issue
8
Year of publication
1996
Pages
762 - 768
Database
ISI
SICI code
0014-4754(1996)52:8<762:POCAP->2.0.ZU;2-5
Abstract
In insect antennal extracts, Schleicher et al.(1) showed that protein kinase C (PKC) inhibitors abolish the transience of pheromone-induced rapid inositol trisphosphate responses, which suggests that pheromonal signals act on phosphorylation of specific proteins. To confirm this hypothesis, we studied the effects of second messengers and a pheromon al blend on phosphorylation of antennal proteins in the cockroach Peri planeta americana. Proteins from adult male antennae were phosphorylat ed in vitro in the presence of [gamma(32)P]adenosine triphosphate, the n separated by SDS-polyacrylamide gel electrophoresis. Numerous phosph opolypeptides were visualized. The presence of Ca++/calmodulin in the incubation medium resulted in increased phosphorylation of polypeptide s with molecular weights of 38, 48, 51, 54 and 58 kDa. Stimulation of PKC by addition of Ca++ phosphatidylserine (PS)/phorbol myristate acet ate (PMA) resulted in the appearance of three phosphopolypeptides of 3 6, 70 and 120 kDa. In the presence of cyclic adenosine monophosphate, two new major polypeptides of 46 and 42 kDa appeared; the latter polyp eptide also appeared in the presence of cyclic guanosine monophosphate . Comparison with polypeptide composition of tissue from the cerci, le g, brain and fat body showed that the 36 and 48 kDa polypeptides were specific to antennae, whereas the 120 kDa polypeptide was also present in the adult brain. When antennae are subjected to pheromonal stimula tion for 16 seconds prior to homogenization, in vitro phosphorylation of the 120, 70, 64 and 38 kDa polypeptides was inhibited, whereas phos phorylation of the 58, 54, 51 and 48 kDa polypeptides was strongly sti mulated. It is noteworthy that a 107 kDa polypeptide was observed only after pheromonal stimulation by Ca++/PS/PMA. Our findings suggest tha t Ca++- and PKC-dependent protein phosphorylation systems play an impo rtant role in the transduction of pheromonal signals in antennae of ma le cockroach P. americana. We speculate that specific phosphoproteins may modulate sensitivity and signal amplification during the olfactory transduction process.