Aldolases a and C are ribonucleolytic components of a neuronal complex that regulates the stability of the light-neurofilament mRNA.
J Neurosci
; 25(17): 4353-64, 2005 Apr 27.
Article
in En
| MEDLINE
| ID: mdl-15858061
ABSTRACT
A 68 nucleotide segment of the light neurofilament (NF-L) mRNA, spanning the translation termination signal, participates in regulating the stability of the transcript in vivo. Aldolases A and C, but not B, interact specifically with this segment of the transcript in vitro. Aldolases A and C are glycolytic enzymes expressed in neural cells, and their mRNA binding activity represents a novel function of these isozymes. This unsuspected new activity was first uncovered by Northwestern blotting of a brainstem/spinal cord cDNA library. It was confirmed by two-dimensional fractionation of mouse brain cytosol followed by Northwestern hybridization and protein sequencing. Both neuronal aldolases interact specifically with the NF-L but not the heavy neurofilament mRNA, and their binding to the transcript excludes the poly(A)-binding protein (PABP) from the complex. Constitutive ectopic expression of aldolases A and C accelerates the decay of a neurofilament transgene (NF-L) driven by a tetracycline inducible system. In contrast, mutant transgenes lacking mRNA sequence for aldolase binding are stabilized. Our findings strongly suggest that aldolases A and C are regulatory components of a light neurofilament mRNA complex that modulates the stability of NF-L mRNA. This modulation likely involves endonucleolytic cleavage and a competing interaction with the PABP. Interactions of aldolases A and C in NF-L expression may be linked to regulatory pathways that maintain the highly asymmetrical form and function of large neurons.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Gene Expression Regulation
/
Neurofilament Proteins
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Fructose-Bisphosphate Aldolase
Limits:
Animals
/
Humans
Language:
En
Journal:
J Neurosci
Year:
2005
Type:
Article
Affiliation country:
United States