Transcriptional regulation by cholecystokinin-pancreozymin in rat pancreas.
Cholecystokinin-pancreozymin (CCK-PZ) is involved in the regulation of pancreatic protein synthesis and secretion. We demonstrate here that CCK-PZ also stimulates RNA synthesis. Rats were killed 0, 30, 60, 120, 240 or 480 min after intraperitoneal injection of CCK-PZ (8 U/kg). Nuclei were prepared from pancreata and used for in vitro RNA synthesis ('run-on' experiments) in the presence of [alpha-32P]UTP. Total RNA synthesis increased after CCK-PZ with maximum UTP incorporation at 60 min. Contributions of RNA polymerase II, responsible for mRNA synthesis, and RNA polymerases I and III could be separately estimated by using alpha-amanitin. RNA polymerase I and III activities increased by 68% after CCK-PZ, whereas RNA polymerase II activity increased by 113%. Rates of synthesis of amylase, chymotrypsinogen B, trypsinogen I and actin mRNAs were estimated by quantitative hybridization of newly synthesized transcripts to specific cDNA clones. Synthesis of the four RNAs increased with a maximum between 60 and 120 min after CCK-PZ, stimulation being more important for the serine proteinases than for amylase. It was concluded that, in rat pancreas, CCK-PZ controls gene expression at the transcriptional level.
Iovanna
J L
JL
INSERM U 315, Marseille, France.
Calvo
E L
EL
Dagorn
J C
JC
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism / Q000502:physiology; D002766:Cholecystokinin / Q000494:pharmacology* / Q000502:physiology; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009693:Nucleic Acid Hybridization; D010179:Pancreas / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D012313:RNA / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects* / Q000502:physiology; D014544:Uridine Triphosphate / Q000378:metabolism
D012333:RNA, Messenger; D012313:RNA; D004247:DNA; D002766:Cholecystokinin; D014544:Uridine Triphosphate