tailieunhanh - Báo cáo Y học: Leucine aminopeptidase during meiotic development

We found a leucine aminopeptidase (LAP; EC ) to be abundant in meiotic prophase tissue of a basidiomycete, Coprinus cinereus. After direct puri®cation of the amino-peptidase component from meiocytes, we cloned the gene by degenerate PCR using partial amino-acid sequences of the puri®ed enzyme and 5¢ and 3¢ RACE. It was homologous to the eukaryotic leucine aminopeptidase gene. | Eur. J. Biochem. 269 826-832 2002 FEBS 2002 Leucine aminopeptidase during meiotic development Takashi Ishizaki1 Aki Tosaka1 Takavuki Nara1 t. Narumichi Aoshima1. Satoshi Namekawa1 B B B B B Kei Watanabe1 Fumika Hamada1 Akira Omori2 and Kengo Sakaguchi1 1 Department of Applied Biological Science Faculty of Science and Technology Tokyo University of Science Noda Chiba Japan Mitsubishi Kasei Institute of Life Sciences Machida Tokyo Japan We found a leucine aminopeptidase LAP EC to be abundant in meiotic prophase tissue of a basidiomycete Coprinus cinereus. After direct purification of the aminopeptidase component from meiocytes we cloned the gene by degenerate PCR using partial amino-acid sequences of the purified enzyme and 5 and 3 RACE. It was homologous to the eukaryotic leucine aminopeptidase gene. The recombinant protein possesses the characteristic activities of a Coprinus leucine aminopeptidase CoLAP with a molecular mass of kDa and forms a homohexamer. Northern blot and spatial distribution analysis by immunohistochemical staining indicated CoLAP to be abundant in meiotic prophase cells and the supporting cells around meiocytes but scarce in mycelium cells. Interestingly from zygotene to pachytene CoLAP was mostly present in supporting cells around meiocytes but from diplotene onwards it was plentiful in meiocytes themselves suggesting that its expression is required to control some of the biochemical events at meiotic prophase. Moreover the strong expression of CoLAP mRNA immediately after treatment with methyl methanesulfonate in mycelium implies that CoLAP has a role in somatic DNA repair. Keywords CoLAP Coprinus cinereus leucine aminopeptidase meiotic prophase. We have investigated meiosis-related protein factors using meiotic cells in a basidiomycete Coprinus cinereus 1-12 . In meiosis chromosomes condense from the dispersed state typical of interphase during early meiotic prophase to form long thin threads in leptotene and each acquires a .