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Introduction of bisecting GlcNAc in N‐glycans of adenylyl cyclase III enhances its activity
Author(s) -
Takahashi Motoko,
Li Wei,
Shibukawa Yukinao,
Yokoe Shunichi,
Gu Jianguo,
Miyoshi Eiji,
Honke Koichi,
Taniguchi Naoyuki
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.lb27-c
Subject(s) - adenylyl cyclase , chemistry , forskolin , downregulation and upregulation , creb , glycosylation , intracellular , enzyme , glycan , signal transduction , phosphorylation , extracellular , microbiology and biotechnology , biochemistry , receptor , gene , biology , transcription factor , glycoprotein
Adenylyl cyclases (ACs) catalyze the synthesis of cAMP in response to extracellular and intracellular signals, and are responsible for wide variety of biological activities. The enzyme β1, 4‐ N ‐acetylglucosaminyltransferase III (GnT‐III) catalyzes the addition of a bisecting N‐acetylglucosamine (GlcNAc) to N‐glycans. In this study, we report on the effects of a bisecting GlcNAc on AC signaling. We established GnT‐III stable expressing cell lines of Neuro‐2a mouse neuroblastoma cells and B16 mouse melanoma cells. Forskolin‐induced AC activation and downstream signalings, such as the synthesis of cAMP and the phosphorylation of transcriptional factor CREB were upregulated in the GnT‐III transfectants. Since endogenous AC expression levels in Neuro‐2a and B16 cells were too low to permit the glycosylation status to be examined, AC type III (ACIII) was overexpressed in a stable expression system using Flp‐In‐293 cells. The N‐glycans of ACIII in the GnT‐III transfectants were confirmed to be modified by the introduction of a bisecting GlcNAc, and AC activity was found to be significantly upregulated in the GnT‐III transfectants. Thus, structure of N‐glycans of ACIII regulate its enzymatic activity and downstream signaling.