AXONEMAL TUBULIN POLYGLYCYLATION PROBED WITH 2 MONOCLONAL-ANTIBODIES - WIDESPREAD EVOLUTIONARY DISTRIBUTION, APPEARANCE DURING SPERMATOZOANMATURATION AND POSSIBLE FUNCTION IN MOTILITY

Two monoclonal antibodies, AXO 49 and TAP 952, probed with carboxy-ter minal peptides from Paramecium axonemal tubulin and with polyglycylate d synthetic peptides, are found to recognize differently tubulin polyg lycylation, the most recently identified posttranslational modificatio n discovered in Paramecium axonemal tubulin. With these antibodies, we show that tubulin polyglycylation is widely distributed in organisms ranging from ciliated protozoa to mammals; it arose early in the cours e of evolution, but seems to be absent in primitive protozoa such as t he Euglenozoa. Tubulin polyglycylation is the last posttranslational m odification which takes place in the course of Drosophila spermatogene sis and its occurrence corresponds to the end of spermatozoan maturati on. An involvement of polyglycylated tubulin in axoneme motility is su ggested since AXO 49 and TAP 952 specifically inhibit the reactivated motility of sea urchin spermatozoa.