EurekaMag.com logo
+ Site Statistics
References:
53,214,146
Abstracts:
29,074,682
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

The molecular basis for a cytosolic malic enzyme null mutation malic enzyme messenger rna from mod 1 null mice contains an internal in frame duplication that extends the coding sequence by 522 nucleotides


Journal of Biological Chemistry 263(9): 4494-4499
The molecular basis for a cytosolic malic enzyme null mutation malic enzyme messenger rna from mod 1 null mice contains an internal in frame duplication that extends the coding sequence by 522 nucleotides
Many tissues from wild type mice express cytosolic malic enzyme activity and contain two mRNAs (2.0 and 3.1 kilobases (kb)) that encode a single 64-kDa malic enzyme subunit polypeptide. MOD-1 null mutant mice lack cytosolic malic enzyme activity but express 2.5- and 3.6-kb mRNAs that hybridize with wild type malic enzyme cDNAs and are induced in liver by a starvation/carbohydrate refeeding regimen. To investigate the basis of the MOD-1 null mutation, a .lambda.gt11 cDNA library was constructed using mRNA from the livers of induced MOD-1 null mice as a template. A recombinant phage with a 2-kb insert was isolated by screening with wild type malic enzyme cDNA probes. The subcloned insert exhibited an atypical (non-wild type) restriction pattern and was subjected to sequence analysis. MOD-1 null malic enzyme cDNA contains an internal tandemly duplicated sequence that corresponds to nucleotides 1027-1548 in the coding region of wild type murine malic enzyme cDNA (Bagchi, S., Wise, L.S., Brown, M.L., Bregman, D., Sul, H.S., and Rubin, C.S. (1987) J. Biol. Chem. 262, 1558-1565). An open reading frame is retained throughout the duplicated sequence. The discovery of a 522-nucleotide in-frame duplication accounts for the increased size of MOD-1 null malic enzyme mRNAs and suggest that a variant malic enzyme polypeptide that is 19 kDa larger than the wild type subunit might be found in mutant mice. Western immunoblot analysis disclosed that MOD-1 null liver cytosol contains an 82-kDa protein that is recognized by anti-malic enzyme antibodies. Under stringent conditions, an anti-sense 32P-oligonucleotide that spans the abnormal junction between the reiterated sequences hybridized with the 2.5 and 3.6-kb MOD-1 null malic enzyme mRNAs but failed to form stable complexes with wild type malic enzyme mRNAs. Thus, both MOD-1 null malic enzyme mRNAS contain the duplication deduced from cDNA sequence analyses. The MOD-1 null mutation might originate from an unequal crossover between homologous regions of two different introns in the malic enzyme gene, thereby causing the duplication of one or more exons.

(PDF 0-2 workdays service: $29.90)

Accession: 006719788



Related references

The molecular basis for a cytosolic malic enzyme null mutation. Malic enzyme mRNA from MOD-1 null mice contains an internal in-frame duplication that extends the coding sequence by 522 nucleotides. Journal of Biological Chemistry 263(9): 4494-4499, 1988

Cloning of complementary dna sequences from murine malic enzyme and the identification of aberrantly large malic enzyme messenger rna in mod 1 null mice. Journal of Biological Chemistry 259(1): 555-559, 1984

Molecular basis for a malic enzyme null mutation. Federation Proceedings 46(6): 2014, 1987

Cloning of cDNA sequences for murine malic enzyme and the identification of aberrantly large malic enzyme mRNA in MOD-1 null mice. Journal of Biological Chemistry 259(1): 555-559, 1984

Kinetics of induction by thyroid hormone of the two hepatic messenger rna coding for cytosolic malic enzyme in the hypothyroid and euthyroid states evidence against an obligatory role of s14 protein in malic enzyme gene expression. Journal of Biological Chemistry 264(33): 19784-19789, 1989

A cloned complementary dna for duck malic enzyme detects abnormally large malic enzyme ec 1.1.1.40 messenger rna species in a strain of mice mod 1n that does not express malic enzyme protein. Biochemistry 23(15): 3454-3459, 1984

A null mutation of cytoplasmic malic enzyme in mice. Molecular and Cellular Biochemistry 30(3): 143-149, 1980

A null mutation of cytoplasmic malic enzyme ec 1.1.1.40 in mice. Molecular and Cellular Biochemistry 30(3): 143-150, 1980

Molecular cloning of a complementary dna sequence for rat malic enzyme ec 1.1.1.40 direct evidence for induction in vivo of rat liver malic enzyme messenger rna by thyroid hormone. Journal of Biological Chemistry 258(20): 12712-12717, 1983

Kinetics of induction by thyroid hormone of the two hepatic mRNAs coding for cytosolic malic enzyme in the hypothyroid and euthyroid states. Evidence against an obligatory role of S14 protein in malic enzyme gene expression. Journal of Biological Chemistry 264(33): 19784-9, 1989