PMID- 22238347
OWN - NLM
STAT- MEDLINE
DCOM- 20120424
LR  - 20211021
IS  - 1083-351X (Electronic)
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 287
IP  - 10
DP  - 2012 Mar 2
TI  - Substrate specificities and intracellular distributions of three N-glycan 
      processing enzymes functioning at a key branch point in the insect 
      N-glycosylation pathway.
PG  - 7084-97
LID - 10.1074/jbc.M111.296814 [doi]
AB  - Man(alpha1-6)[GlcNAc(beta1-2)Man(alpha1-3)]ManGlcNAc(2) is a key branch point intermediate 
      in the insect N-glycosylation pathway because it can be either trimmed by a 
      processing beta-N-acetylglucosaminidase (FDL) to produce paucimannosidic N-glycans 
      or elongated by N-acetylglucosaminyltransferase II (GNT-II) to produce complex 
      N-glycans. N-acetylglucosaminyltransferase I (GNT-I) contributes to branch point 
      intermediate production and can potentially reverse the FDL trimming reaction. 
      However, there has been no concerted effort to evaluate the relationships among 
      these three enzymes in any single insect system. Hence, we extended our previous 
      studies on Spodoptera frugiperda (Sf) FDL to include GNT-I and -II. Sf-GNT-I and 
      -II cDNAs were isolated, the predicted protein sequences were analyzed, and both 
      gene products were expressed and their acceptor substrate specificities and 
      intracellular localizations were determined. Sf-GNT-I transferred 
      N-acetylglucosamine to Man(5)GlcNAc(2), Man(3)GlcNAc(2), and 
      GlcNAc(beta1-2)Man(alpha1-6)[Man(alpha1-3)]ManGlcNAc(2), demonstrating its role in branch 
      point intermediate production and its ability to reverse FDL trimming. Sf-GNT-II 
      only transferred N-acetylglucosamine to 
      Man(alpha1-6)[GlcNAc(beta1-2)Man(alpha1-3)]ManGlcNAc(2), demonstrating that it initiates 
      complex N-glycan production, but cannot use Man(3)GlcNAc(2) to produce hybrid or 
      complex structures. Fluorescently tagged Sf-GNT-I and -II co-localized with an 
      endogenous Sf Golgi marker and Sf-FDL co-localized with Sf-GNT-I and -II, 
      indicating that all three enzymes are Golgi resident proteins. Unexpectedly, 
      fluorescently tagged Drosophila melanogaster FDL also co-localized with Sf-GNT-I 
      and an endogenous Drosophila Golgi marker, indicating that it is a Golgi resident 
      enzyme in insect cells. Thus, the substrate specificities and physical 
      juxtapositioning of GNT-I, GNT-II, and FDL support the idea that these enzymes 
      function at the N-glycan processing branch point and are major factors 
      determining the net outcome of the insect cell N-glycosylation pathway.
FAU - Geisler, Christoph
AU  - Geisler C
AD  - Department of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071, 
      USA.
FAU - Jarvis, Donald L
AU  - Jarvis DL
LA  - eng
SI  - GENBANK/HQ888863
SI  - GENBANK/HQ888864
GR  - R01 GM049734/GM/NIGMS NIH HHS/United States
GR  - R01GM49734/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
DEP - 20120111
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (DNA, Complementary)
RN  - 0 (Insect Proteins)
RN  - 0 (Oligosaccharides)
RN  - EC 2.4.1.- (N-Acetylglucosaminyltransferases)
RN  - V956696549 (Acetylglucosamine)
SB  - IM
MH  - Acetylglucosamine/genetics/metabolism
MH  - Animals
MH  - Base Sequence
MH  - DNA, Complementary/genetics
MH  - Glycosylation
MH  - Golgi Apparatus/*enzymology/genetics
MH  - Insect Proteins/genetics/*metabolism
MH  - Insecta/*enzymology/genetics
MH  - Molecular Sequence Data
MH  - N-Acetylglucosaminyltransferases/genetics/*metabolism
MH  - Oligosaccharides/*biosynthesis/genetics
PMC - PMC3293541
EDAT- 2012/01/13 06:00
MHDA- 2012/04/25 06:00
PMCR- 2013/03/02
CRDT- 2012/01/13 06:00
PHST- 2012/01/13 06:00 [entrez]
PHST- 2012/01/13 06:00 [pubmed]
PHST- 2012/04/25 06:00 [medline]
PHST- 2013/03/02 00:00 [pmc-release]
AID - S0021-9258(20)61026-2 [pii]
AID - M111.296814 [pii]
AID - 10.1074/jbc.M111.296814 [doi]
PST - ppublish
SO  - J Biol Chem. 2012 Mar 2;287(10):7084-97. doi: 10.1074/jbc.M111.296814. Epub 2012 
      Jan 11.