Biologic contribution of P1 promoter-mediated expression of ST6Gal I sialyltransferase.
The synthesis of the common and well-documented Siaalpha 2,6 to Galbeta 1,4GlcNAc structure (Sia6LacNAc) is principally mediated by the sialyltransferase ST6Gal I, which is particularly highly expressed in liver, lactating mammary gland, intestinal epithelia of newborn animals, and B cells. Multiple independent promoters govern the expression of Siat1, the ST6Gal I gene. In liver, elevation of hepatic and serum ST6Gal is part of the acute phase reaction, the hepatic response to systemic trauma, and is governed by the inducible, liver-specific promoter-regulatory region, P1. A constitutive and nontissue-specific promoter, P3, mediates low-level, basal hepatic Siat1 transcription. We generated a mouse specifically unable to use the transcriptional initiation site uniquely used in P1-mediated ST6Gal I expression. These animals, Siat1deltaP1, are viable and display reduced ST6Gal I mRNA in liver with concomitantly reduced sialyltransferase activities in liver and in serum. Siat1deltaP1 animals are unable to elevate hepatic Siat1 mRNA as part of the inflammatory response induced by turpentine. Surprisingly, serum glycoprotein components exhibit normal extent of sialylation, with no noticeable difference in binding to SNA, the alpha2,6-sialyl-specific lectin. Siat1deltaP1 animals also exhibit an outwardly normal B cell response. On intraperitoneal challenge with the pathogen Salmonella typhimurium, a significantly greater accumulation of neutrophils within the peritoneal space was observed in Siat1deltaP1 animals compared to wild-type mice. Siat1deltaP1 mice also exhibit a greater bacterial burden in liver and spleen, accompanied by more pronounced spleno-/hepatomegaly and greater leukocyte infiltration into affected organs than their wild-type counterparts.
Appenheimer
Michelle M
MM
The Department of Molecular and Cellular Biology, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA.
Huang
Ruea-Yea
RY
Chandrasekaran
E V
EV
Dalziel
Martin
M
Hu
Yi Ping
YP
Soloway
Paul D
PD
Wuensch
Sherry A
SA
Matta
Khushi L
KL
Lau
Joseph T Y
JT
D000210:Acute-Phase Reaction / Q000201:enzymology / Q000276:immunology / Q000382:microbiology; D000818:Animals; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D008099:Liver / Q000382:microbiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000276:immunology; D009928:Organ Specificity; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011995:Recombination, Genetic / Q000235:genetics; D012480:Salmonella Infections / Q000201:enzymology / Q000276:immunology / Q000382:microbiology; D012486:Salmonella typhimurium / Q000276:immunology; D017384:Sequence Deletion / Q000235:genetics; D012799:Sialyltransferases / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D013154:Spleen / Q000382:microbiology; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D012799:Sialyltransferases; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase