| First Author | Hagenbüchle O | Year | 1985 |
| Journal | J Mol Biol | Volume | 185 |
| Issue | 2 | Pages | 285-93 |
| PubMed ID | 3877171 | Mgi Jnum | J:147629 |
| Mgi Id | MGI:3841577 | Doi | 10.1016/0022-2836(85)90404-8 |
| Citation | Hagenbuchle O, et al. (1985) Expression of mouse Amy-2a alpha-amylase genes is regulated by strong pancreas-specific promoters. J Mol Biol 185(2):285-93 |
| abstractText | Three types of Amy-2-related DNA sequences, Amy-2a I, Amy-2a II and Amy-X, exist in the genome of mice of the inbred strain A/J. Amy-2a I and Amy-X are single copy sequences. Amy-2a II occurs as three copies per haploid genome. DNA sequence analysis reveals that both classes of Amy-2a genes specify the same unique pancreatic alpha-amylase mRNA species, since they share common exon sequences. Four independently cloned Amy-2a II isolates were found to be identical in all regions sequenced. This suggests that most, if not all, chromosomal Amy-2a II copies are identical. Amy-X is presumably a pseudogene, since its exon sequences, which are distinct from those of Amy-2a, are not detected in pancreatic alpha-amylase mRNA. We have determined the transcriptional activities of the Amy-2a genes by mapping in vitro elongated nascent transcripts to Amy-2a restriction fragments. Transcription initiation occurs at or close to the cap site. The expression of Amy-2a in vivo is under control of strong promoters, which are active exclusively in the pancreas. The accumulation of alpha-amylase mRNA in cells of the exocrine pancreas is regulated mainly at the transcriptional level. We have searched for pancreatic transcripts of Amy-1a, which specifies both parotid gland and liver-type alpha-amylase mRNAs. Surprisingly, the weak Amy-1a promoter, which directs the synthesis of the mRNA containing the liver-type leader sequence, also is active in the pancreas and, hence, in all alpha-amylase-producing tissues. |
