Biomedical subjects

D K Ann

Publications and source records attributed to D K Ann.

41 records · Page 3Linked to original sources

PubMed1987

Induction of proline-rich proteins in hamster salivary glands by isoproterenol treatment and an unusual growth inhibition by tannins.

Treatment of hamsters with the beta-agonist isoproterenol caused a dramatic increase in a series of unusual proteins in the parotid and submandibular glands. These proteins are acid soluble and they contain high amounts (mol%) of glutamate plus glutamine (30-35), proline (23-30), and glycine (12-25). Three proteins (HP45, HP43a, and HP43b) were isolated from trichloroacetic acid extracts of parotid glands of isoproterenol-treated hamsters. The basic protein (HP45) was not retained by DEAE-cellulose and did not contain phosphate or carbohydrate. Two acidic proteins (HP43a and HP43b) had the same apparent molecular weight on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but these were separated by DEAE-cellulose chromatography. HP43a and HP43b contained 4.3 and 5.7 phosphate residues/mol of protein, respectively. Levels of mRNAs encoding this series of proteins showed striking increases following isoproterenol treatment as determined by cell-free translations and Northern analysis. Feeding tannins to rats and mice mimicks the effects of isoproterenol treatment on the parotid gland (Mehansho, H., Hagerman, A., Clements, S., Butler, L., Rogler, J., and Carlson, D.M. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 3948-3952; Mehansho, H., Clements, S., Sheares, B. T., Smith, S., and Carlson, D. M. (1985) J. Biol. Chem. 260, 4418-4423]. However, hamsters on a high tannin diet (2%) did not respond like rats and mice and instead displayed an unusual growth inhibition. Weanling hamsters maintained on a 2% tannin diet initially lost weight for 3 days and then failed to gain weight for up to 6 months when kept on this diet. Essentially a normal growth rate was observed when the tannin-fed hamsters were switched to a normal diet.

Adenylyl Cyclases↗

PubMed1987

Structure, organization, and regulation of a hamster proline-rich protein gene. A multigene family.

Genomic DNA fragments bearing proline-rich protein (PRP) genes expressed specifically in hamster parotid glands have been isolated and characterized. Complete exonic sequences as well as intronic and a considerable portion of the flanking sequences are reported for a PRP gene, H29. H29 is interrupted by three intervening sequences, with consensus splice junctions, and it likely encodes the acidic hamster PRP Hp43a. Exceedingly high homology of the 5'-untranslated region and the sequence encoding the signal peptide is observed with other PRPs of all species studied. Significant homology was also detected among the repetitive sequences of the mature acidic PRPs from human, mouse, hamster, and rat. This conservation of the internal repeats of the PRPs suggested that proline-rich protein gene evolution involved intragenic duplication of internal repeats and gene duplication and conversion. Both hamster and mouse PRP genes (H29 and mouse proline-rich protein gene, respectively) share considerable sequence similarity in the 5'-flanking regions for about 100 base pairs upstream. The remainder of the upstream sequences were heterologous except for three oligonucleotide regions with 60-70% sequence conservation. These three regions are thought to be involved in the regulation of the tissue-specific PRP gene induction.

Amino Acids↗

PubMed1987

Induction of tissue-specific proline-rich protein multigene families in rat and mouse parotid glands by isoproterenol. Unusual strain differences of proline-rich protein mRNAs.

A dramatic induction of proline-rich protein mRNAs by the beta-agonist isoproterenol in the parotid and submandibular glands of both rats and mice has been demonstrated using Northern and dot-blot hybridizations and cell-free translation. Proline-rich protein mRNAs were either very low or not detectable in glands of control rats and mice. After 4 days of isoproterenol treatment, mRNAs encoding these unusual proteins comprised over 50% of the total glandular mRNAs. A 2-4-fold increase in proline-rich protein mRNAs was observed in rat parotid glands as soon as 4 h after treatment. The rat proline-rich protein multigene family encodes two groups of mRNAs with sizes ranging from 600 to 1100 bases. Cell-free translations gave about 10-12 proline-rich proteins. In glands of isoproterenol-treated mice, major species of proline-rich protein mRNAs were observed at 1050 and 1300 bases for BALB/cJ and DBA/2J mice and at 1100 and 1200 bases for CD-1 and C57BL/6J mice. Cell-free translations showed unusual differences in proteins synthesized from the four strains after isoproterenol treatment. AtT20 cells were transfected with a mouse proline-rich protein gene inserted into the plasmid pUC8 (pUMP2-BE). Transcription of proline-rich protein mRNA was induced by exposing these transfected cells to either isoproterenol or cAMP, plus theophylline.

Animals↗

PubMed1985

The structure and organization of a proline-rich protein gene of a mouse multigene family.

One gene of the mouse proline-rich protein multigene family was cloned on a 3.6-kilobase pair EcoRI/BglII DNA fragment from a (partial) Sau3A bacteriophage library of CD-1 mouse chromosomal DNA. Phage harboring the gene were identified by plaque hybridization using 32P-labeled proline-rich protein cDNA inserts from clones pRP33 and pMP1 obtained from rat and mouse, respectively. The transcriptional unit includes three exonic sequences separated by 1434 base pairs (intron I) and 450 base pairs (intron II). The complete primary structure of the gene and the 5' and 3' flanking regions (3595 base pairs) were determined by the Maxam and Gilbert (Maxam, A.M., and Gilbert, W. (1980) Methods Enzymol. 65, 499-560) sequencing method. The DNA on the 5' side of exon I contains several sequences that may be involved in the induction and expression of this mouse gene. These sequences include putative regulatory sites such as those considered to be inducible by cAMP and steroids, Z-DNA and enhancer sequences and the expected TATAA and CAAT boxes. The mature protein coding region, exon II, is not interrupted with intron sequences. Exon III is located in the nontranslated region and contains the poly(A) addition site. The deduced amino acid sequence showed that the protein encoded by this gene contains 13 tandemly repeat regions, each 14 amino acids in length, with the prototype sequence PPPPGGPQPRPPQG. Each amino acid within the repeat has a favored codon. The consensus DNA sequence for each repeat is CCA CCA CCA CCA GGA GGC CCA CAG CCG AGA CCC CCT CAA GGC. The high degree of conservation of both nucleotide and amino acid sequences within the repeat region suggests that proline-rich protein genes likely evolved by gene duplication of a 42-base pair internal repeat.

Amino Acid Sequence↗

PubMed1984

Nucleotide sequence analysis of a proline-rich protein cDNA and peptide homologies of rat and human proline-rich proteins.

Plasmids containing cDNAs for proline-rich proteins have been isolated from a cDNA library prepared from parotid glands of isoproterenol-treated rats. The nucleotide sequence of one of these cDNAs (pRP33) has been determined, and it encodes an acidic proline-rich protein. The N-terminal 13 amino acids are highly hydrophobic and may be part of a signal peptide. The next 66 amino acids constitute an acidic domain which is interrupted by a short (8 residue) basic region. The sequence beginning at proline 80 contains six tandemly repeated regions of 18 to 19 amino acids in length with the prototype sequence PPPQGGPQXPPQPGXPQG. Two pairs of these repeats (amino acid residues 116 to 152 and 153 to 189) are 93% homologous in nucleotide sequence. The high homology in both nucleotide and amino acid sequences in the repeat region suggests that this protein may have evolved by duplication of internal portions of a progenitor gene.

Amino Acid Sequence↗