Intracellular localization of MAP2-related protein (O-map) in prophase I and metaphase II oocytes of Xenopus.
An antibody directed against rat brain microtubule-associated protein 2 (MAP2) immunoprecipitated a protein of 240 kDa from a Xenopus oocyte extract. In contrast, in Xenopus brain extract, this antibody recognizes a protein of 280 kDa. The oocyte MAP2-related protein (called O-MAP) is present in both prophase I and metaphase II-blocked oocytes as demonstrated by immunoblotting experiments; it is in vivo phosphorylated. Immunocytochemical studies using the anti-rat brain MAP2 antibody demonstrated that the O-MAP colocalizes within the cortical microtubular array present in both prophase I and metaphase II oocytes. However, O-MAP is not associated with the microtubular structures which are organized during the oocyte prophase-metaphase transition, i.e., a giant cytoplasmic network and both the meiotic spindles. O-MAP therefore appears as a microtubule-associated protein oocyte specific and may play a role in the regulation of microtubule stability and the organization of the oocyte cytoskeleton.
Fellous
A
A
Unité INSERM 96, Bicêtre, France.
Huchon
D
D
Thibier
C
C
Jessus
C
C
D000818:Animals; D015151:Immunoblotting; D008677:Metaphase / Q000502:physiology; D008869:Microtubule-Associated Proteins / Q000032:analysis*; D008870:Microtubules / Q000737:chemistry; D009865:Oocytes / Q000737:chemistry* / Q000166:cytology; D011233:Precipitin Tests; D011418:Prophase / Q000502:physiology; D014981:Xenopus
D008869:Microtubule-Associated Proteins