GSBS Student Publications

Title

The rat gene encoding neurotensin and neuromedin N. Structure, tissue-specific expression, and evolution of exon sequences

GSBS Program

Biochemistry & Molecular Pharmacology

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Molecular Genetics and Microbiology

Date

4-5-1988

Document Type

Article

Medical Subject Headings

Amino Acid Sequence; Animals; Base Sequence; Cattle; DNA Restriction Enzymes; Dogs; *Evolution; *Exons; *Genes; Hypothalamus; Male; Molecular Sequence Data; Neurotensin; Organ Specificity; Peptide Fragments; Rats; Sequence Homology, Nucleic Acid; Species Specificity; Testis; *Transcription, Genetic

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Recombinant DNA clones encoding the neurotensin/neuromedin N precursor protein have been isolated from both bovine hypothalamus cDNA and rat genomic libraries using a heterologous canine cDNA probe. Nucleotide sequence analysis of these clones and comparison with the previously determined canine sequence has revealed that 76% of the amino acid residues are conserved in all three species. The protein precursor sequences predicted from bovine hypothalamus and canine intestine cDNA clones vary at only 9 of 170 amino acid residues suggesting that within a species identical precursors are synthesized in both the central nervous system and intestine. The rat gene spans approximately 10.2 kilobases (kb) and is divided into four exons by three introns. The neurotensin and neuromedin N coding domains are tandemly positioned on exon 4. RNA blot analysis has revealed that the rat gene is transcribed to yield two distinct mRNAs, 1.0 and 1.5 kb in size, in all gastrointestinal and all neural tissues examined except the cerebellum. There is a striking variation in the relative levels of these two mRNAs between brain and intestine. The smaller 1.0-kb mRNA greatly predominates in intestine while both mRNA species are nearly equally abundant in hypothalamus, brain stem, and cortex. Sequence comparisons and RNA blot analysis indicate that these two mRNAs result from the differential utilization of two consensus poly(A) addition signals and differ in the extent of their 3' untranslated regions. The relative combined levels of the mRNAs in various brain and intestine regions correspond roughly with the relative levels of immunologically detectable neurotensin except in the cerebral cortex where mRNA levels are 6 times higher than anticipated.

Rights and Permissions

Citation: J Biol Chem. 1988 Apr 5;263(10):4963-8.

Related Resources

Link to article in PubMed

Journal Title

The Journal of biological chemistry

PubMed ID

2832414