Document Detail

Overexpression of spermidine/spermine N1-acetyltransferase under the control of mouse metallothionein I promoter in transgenic mice: evidence for a striking post-transcriptional regulation of transgene expression by a polyamine analogue.
MedLine Citation:
PMID:  10024505     Owner:  NLM     Status:  MEDLINE    
We recently generated a transgenic mouse line overexpressing spermidine/spermine N1-acetyltransferase (SSAT) gene under its own promoter. The tissue polyamine pools of these animals were profoundly affected and the mice were hairless from early age. We have now generated another transgenic-mouse line overexpressing the SSAT gene under the control of a heavy-metal-inducible mouse metallothionein I (MT) promoter. Even in the absence of heavy metals, changes in the tissue polyamine pools indicated that a marked activation of polyamine catabolism had occurred in the transgenic animals. As with the SSAT transgenic mice generated previously, the mice of the new line (MT-SSAT) suffered permanent hair loss, but this occurred considerably later than in the previous SSAT transgenic animals. Liver was the most affected tissue in the MT-SSAT transgenic animals, revealed by putrescine overaccumulation, significant decrease in spermidine concentration and >90% reduction in the spermine pool. Even though hepatic SSAT mRNA accumulated to massive levels in non-induced transgenic animals, SSAT activity was only moderately elevated. Administration of ZnSO4 further elevated the level of hepatic SSAT message and induced enzyme activity, but not more than 2- to 3-fold. Treatment of the transgenic animals with the polyamine analogue N1,N11-diethylnorspermine (DENSPM) resulted in an immense induction, more than 40000-fold, of enzyme activity in the liver of transgenic animals, and minor changes in the SSAT mRNA level. Liver spermidine and spermine pools were virtually depleted within 1-2 days in response to the treatment with the analogue. The treatment also resulted in a marked mortality (up to 60%) among the transgenic animals which showed ultrastructural changes in the liver, most notably mitochondrial swelling, one of the earliest signs of cell injury. These results indicated that, even without its own promoter, SSAT is powerfully induced by the polyamine analogue through a mechanism that appears to involve a direct translational and/or heterogenous nuclear RNA processing control. It is likewise significant that overexpression of SSAT renders the animals extremely sensitive to polyamine analogues.
S Suppola; M Pietilä; J J Parkkinen; V P Korhonen; L Alhonen; M Halmekytö; C W Porter; J Jänne
Related Documents :
24862735 - In vitro reconstitution of a cellular phase-transition process that involves the mrna d...
9952405 - Mutation in neurofilament transgene implicates rna processing in the pathogenesis of ne...
11320405 - Envelope fusion protein binding studies in an inducible model of retrovirus receptor ex...
25394615 - Birth weight is associated with placental fat mass- and obesity-associated gene express...
24040125 - Retinoic acid metabolic genes, meiosis, and gonadal sex differentiation in zebrafish.
19906945 - Analysis of latent viral gene expression in natural and experimental latency models of ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  The Biochemical journal     Volume:  338 ( Pt 2)     ISSN:  0264-6021     ISO Abbreviation:  Biochem. J.     Publication Date:  1999 Mar 
Date Detail:
Created Date:  1999-05-06     Completed Date:  1999-05-06     Revised Date:  2010-09-13    
Medline Journal Info:
Nlm Unique ID:  2984726R     Medline TA:  Biochem J     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  311-6     Citation Subset:  IM    
A.I. Virtanen Institute, University of Kuopio, FIN-70211 Kuopio, Finland.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Acetyltransferases / genetics*,  metabolism
Biogenic Polyamines / metabolism
Gene Expression Regulation, Enzymologic / drug effects*
Liver / drug effects,  enzymology,  metabolism,  ultrastructure
Metallothionein / genetics*
Mice, Transgenic
Microscopy, Electron
RNA Processing, Post-Transcriptional / drug effects*
Spermine / analogs & derivatives*,  pharmacology
Zinc Sulfate / pharmacology
Grant Support
Reg. No./Substance:
0/Biogenic Polyamines; 121749-39-1/N(1),N(11)-diethylnorspermine; 71-44-3/Spermine; 7733-02-0/Zinc Sulfate; 9038-94-2/Metallothionein; EC 2.3.1.-/Acetyltransferases; EC N-acetyltransferase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Overexpression of CuZn superoxide dismutase protects RAW 264.7 macrophages against nitric oxide cyto...
Next Document:  Proteoglycan involvement in polyamine uptake.