Author/Editor		Rozman, Damjana; Seliškar, Matej; Cotman, Marko; Fink, Martina
Title		Pre-cholesterol precursors in gametogenesis
Type		članek
Source		Mol Cell Endocrinol
Vol. and No.		Letnik 234
Publication year		2005
Volume		str. 47-56
Language		eng
Abstract		Meiosis activating sterols (MAS) are biologically active post-lanosterol intermediates of cholesterol biosynthesis that are synthetized primarily in the gonads, including the sperm. MAS reinitiate the meiosis of oocytes in vitro while in vivo they seem to contribute to the oocyte quality and the progression of meiosis. The mRNAs for the MAS-producing enzyme lanosterol 14alpha-demethylase (CYP51) arise by alternative poly (A) signal selection. Only signals with low cleavage activity are used in the testis. Translation of mammalian CYPSIs starts at one of the tandem in-frame ATGs. CYP51 protein of the bull is shorter compared to the human due to the usage of a more downstream translation start site. CYP51 proteins are post-translationally modified by glycosylations in the Golgi and on acrosomal membranes of the sperm. Green fluorescence protein-based ex vivo system has been developed to aid studying the intracellular transport of the MAS-producing CYP51. The influence of the post-translational modifications on MAS-synthesizing capacity is under investigation.
Descriptors		MATURATION-PROMOTING FACTOR CYTOCHROME P-450 GAMETOGENESIS LANOSTEROL DNA, COMPLEMENTARY POLYMERASE CHAIN REACTION LIVER TESTIS RNA PLASMIDS TRANSFECTION PLASMIDS MICROSCOPY, CONFOCAL RNA PROCESSING, POST-TRANSCRIPTIONAL POLY A