Differential potency of two crosslinking plant lectins to induce formation of haptenic-sugar-resistant aggregates of rat thymocytes by post-binding signaling.
To evaluate the significance of post-binding events for stable aggregate formation, the aggregation/dissociation of rat thymocytes initiated by two crosslinking plant lectins, namely concanavalin A (Con A) and Solanum tuberosum agglutinin (STA), were comparatively studied. Despite intimate cell contacts in the aggregates only Con A led to establishment of haptenic-sugar-resistant (HSR) complexes. The presence of inhibitor II of diacylglycerol kinase, a dual calmodulin antagonist/protein kinase C inhibitor (trifluoperazine), and a sulfhydryl group reagent (N-ethylmaleimide) impaired this process. The obtained results indicate that the formation of HSR cellular contacts is not an automatic response to lectin-dependent cell association. In contrast to STA, Con A binding elicits this reaction with involvement of diacylglycerol kinase, protein kinase C and/or calmodulin as well as thiol level perturbation, as inferred by the application of target-selective inhibitors.
Timoshenko
A V
AV
Department of Biophysics, Belarusian State University, Minsk. timoshenko@phys.bsu.unibel.by
Gorudko
I V
IV
Cherenkevich
S N
SN
Gabius
H J
HJ
D000818:Animals; D050260:Carbohydrate Metabolism; D002449:Cell Aggregation; D003208:Concanavalin A / Q000378:metabolism* / Q000494:pharmacology; D003432:Cross-Linking Reagents / Q000378:metabolism* / Q000494:pharmacology; D019852:Diacylglycerol Kinase / Q000378:metabolism; D006241:Haptens / Q000378:metabolism*; D037102:Lectins / Q000378:metabolism* / Q000494:pharmacology; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000378:metabolism; D037121:Plant Lectins; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects; D010738:Type C Phospholipases / Q000378:metabolism
D003432:Cross-Linking Reagents; D006241:Haptens; D037102:Lectins; D037121:Plant Lectins; C041202:potato lectin; D003208:Concanavalin A; D019852:Diacylglycerol Kinase; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D011493:Protein Kinase C; D010738:Type C Phospholipases