Premium
Inhibition of protein synthesis affects histone H1 kinase, but not chromosome condensation activity, during the first meiotic division of pig oocytes
Author(s) -
Kubelka Michal,
Rimkevicova Zora,
Guerrier Pierre,
Motlik Jan
Publication year - 1995
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.1080410110
Subject(s) - cycloheximide , prophase , biology , germinal vesicle , premature chromosome condensation , maturation promoting factor , puromycin , microbiology and biotechnology , metaphase , protein biosynthesis , protein kinase a , histone , phosphorylation , cyclin dependent kinase 1 , histone h1 , meiosis , chromatin , oocyte , biochemistry , chromosome , cell cycle , embryo , dna , cell , gene
The influence of protein synthesis on the regulation of the first meiotic division was studied in pig oocytes. We show that histone H1 kinase activity gradually increases during in vitro culture of pig oocytes, reaching maximum in metaphase I stage after 24 hr of culture. However, in the presence of the protein synthesis inhibitor cycloheximide, histone H1 kinase is not activated during the whole culture period, and after 24 hr it is approximately at the same level as in prophase‐stage oocytes. The gradual increase in phosphorylation of six proteins of molecular weights 39, 48, 53, 66, 96, and 120 kDa, observed during the first 24 hr of culture, was not detected when cycloheximide was added to the culture medium. Similarly, the decrease in phosphorylation of a 90‐kDa protein was not seen in cycloheximide‐treated oocytes. On the other hand, the levels of both MPF components, p34 cdc2 and cyclin B, which were found to be nearly constant during the first meiotic division, were not influenced by cycloheximide treatment as revealed by Western blotting. The process of germinal vesicle breakdown (GVBD) was totally blocked by cycloheximide. The condensation of chromatin, however, was not influenced, suggesting that GVBD and chromosome condensation could be regulated independently. The different degrees of MPF activation involved in these processes, as well as the nature of the protein(s) which must be synthesized for triggering GVBD, are discussed. © 1995 Wiley‐Liss, Inc.