PMID- 8383289
OWN - NLM
STAT- MEDLINE
DCOM- 19930406
LR  - 20131121
IS  - 0888-8809 (Print)
IS  - 0888-8809 (Linking)
VI  - 7
IP  - 1
DP  - 1993 Jan
TI  - Glucocorticoid-regulated stability of a constitutively expressed mouse mammary 
      tumor virus glycoprotein.
PG  - 94-103
AB  - Glucocorticoids regulate the transport and processing of mouse mammary tumor 
      virus (MMTV) glycoproteins in viral-infected HTC rat hepatoma cells. To begin to 
      determine the role of cellular components involved in this steroid-mediated 
      response, a constitutively expressed MMTV glycoprotein gene containing a mutation 
      in the endoproteolytic cleavage site was used to simplify the viral maturation 
      products. Expression of the uncleavable MMTV glycoprotein gene in transfected HTC 
      rat hepatoma cells demonstrated that treatment with the synthetic glucocorticoid 
      dexamethasone resulted in a 5-fold increase in the steady state level of the 
      intracellular and cell surface MMTV glycoproteins. Under these conditions, 
      dexamethasone did not alter the level of MMTV glycoprotein transcripts. 
      Pulse-chase radiolabeling with [35S]methionine demonstrated that dexamethasone 
      did not affect the apparent rate of MMTV glycoprotein translation, and an 
      analysis of oligosaccharide side-chain structure by endoglycosidase-H digestion 
      revealed that glucocorticoids did not alter the 45-min endoplasmic reticulum to 
      Golgi transit time. Pulse-chase kinetic analysis of 4-h pulse-labeled cells 
      revealed that the half-life of the mature glycosylated MMTV polyprotein, gp78, 
      was 105 min in glucocorticoid-treated cells and 45 min in untreated cells. Taken 
      together, our results suggest that glucocorticoids increase the stability of MMTV 
      glycoproteins by a posttranslational mechanism and that this effect may be 
      occurring relatively early in the exocytic pathway.
FAU - Goodman, L J
AU  - Goodman LJ
AD  - Department of Molecular and Cell Biology, University of California, Berkeley 
      94720.
FAU - Firestone, G L
AU  - Firestone GL
LA  - eng
GR  - CA-09041/CA/NCI NIH HHS/United States
GR  - DK-42799/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Mol Endocrinol
JT  - Molecular endocrinology (Baltimore, Md.)
JID - 8801431
RN  - 0 (Antigens, Viral, Tumor)
RN  - 0 (Glycoproteins)
RN  - 0 (Protein Precursors)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 0 (Viral Envelope Proteins)
RN  - 0 (glycoprotein 52 antigen, Mouse mammary tumor virus)
RN  - 7S5I7G3JQL (Dexamethasone)
SB  - IM
MH  - Animals
MH  - Antigens, Viral, Tumor/*biosynthesis/genetics
MH  - Biological Transport/drug effects
MH  - Dexamethasone/*pharmacology
MH  - Exocytosis/drug effects
MH  - Gene Expression Regulation, Viral/*drug effects
MH  - Glycoproteins/*biosynthesis/genetics
MH  - Liver Neoplasms, Experimental
MH  - Mammary Tumor Virus, Mouse/*genetics
MH  - Protein Biosynthesis/drug effects
MH  - Protein Precursors/genetics/*metabolism
MH  - Protein Processing, Post-Translational/*drug effects
MH  - Rats
MH  - Recombinant Fusion Proteins/metabolism
MH  - Transcription, Genetic/drug effects
MH  - Tumor Cells, Cultured
MH  - Viral Envelope Proteins/*biosynthesis/genetics
EDAT- 1993/01/01 00:00
MHDA- 1993/01/01 00:01
CRDT- 1993/01/01 00:00
PHST- 1993/01/01 00:00 [pubmed]
PHST- 1993/01/01 00:01 [medline]
PHST- 1993/01/01 00:00 [entrez]
AID - 10.1210/mend.7.1.8383289 [doi]
PST - ppublish
SO  - Mol Endocrinol. 1993 Jan;7(1):94-103. doi: 10.1210/mend.7.1.8383289.