title: Analyses of chicken sialyltransferases related to N-glycosylation.
abstract: Proteins exogenously expressed and deposited in the egg whites of transgenic chickens did not contain terminal sialic acid in their N-glycan. Since this sugar is important for the biological stability of therapeutic proteins, we examined chicken sialyltransferases (STs). Based on homologies in DNA sequences, we cloned and expressed several chicken STs, which appeared to be involved in N-glycosylation in mammals, in 293FT cells. Enzymatic activity was detected with ST3Gal3, ST3Gal6 and ST6Gal1 using galactose-β1,4-N-acetylglucosamine (Galβ1,4GlcNAc) as an acceptor. Using Golgi fractions from the cell-free extracts of chicken organs, α2,3- and/or α2,6-ST activities were detected in the liver and kidney, but were absent in the oviduct cells in which egg-white proteins were produced. This result suggested that the lack of ST activities in oviduct cells mainly caused the lack of sialic acid in the N-glycan of proteins exogenously expressed and deposited in egg white.
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kojima
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Mizutani
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Okuzaki
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Nishijima
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan. Electronic address: kaneoka@nubio.nagoya-u.ac.jp.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Kaneoka
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Sasamoto
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Miyake
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Iijima
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002474:Cell-Free System; D002645:Chickens / Q000235:genetics; D003001:Cloning, Molecular; D004529:Egg White / Q000737:chemistry; D005260:Female; D005690:Galactose / Q000031:analogs & derivatives / Q000378:metabolism; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D009928:Organ Specificity; D010057:Oviducts / Q000166:cytology / Q000201:enzymology; D012794:Sialic Acids / Q000378:metabolism*; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism*
chemical_list: D012794:Sialic Acids; D012799:Sialyltransferases; D000117:Acetylglucosamine; D005690:Galactose
keywords: Chicken; N-Glycosylation; Oviduct; Sialic acid; Sialyltransferase; Transgenic chicken