Related Experiment Videos
Mouse liver cytochrome P-450 (P-450IIIAM1): its cDNA cloning and inducibility by dexamethasone
T Yanagimoto1, S Itoh, D Muller-Enoch
1Division of Analytical Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
Abstract:
A full-length cDNA complementary to mouse liver mRNA coding for one of the cytochromes P-450 (P-450) in the P-450IIIA family, namely P-450IIIM1, was isolated and completely sequenced. The sequence of this cDNA clone, pMDex13, revealed that it encoded a polypeptide of 504 deduced amino acid residues (Mr = 57,853). The deduced amino acid sequence showed 87.3 and 84.9% identity with rat P-450IIIA1 and P-450IIIA2, respectively. The NH2-terminal 24 amino acid sequences of P-450IIIAM1 were completely identical with purified mouse P-450UT protein. RNA blot analysis showed that mRNA content of hepatic P-450IIIAM1 was remarkably increased by treatment of mice with dexamethasone.
Insights
Researchers isolated and sequenced a mouse liver gene, P-450IIIM1, crucial for drug metabolism. Dexamethasone treatment significantly increased its mRNA levels, indicating its regulation.
Area of Science:
- Biochemistry
- Molecular Biology
- Pharmacology
Background:
- Cytochromes P-450 (P-450) are critical enzymes involved in xenobiotic metabolism.
- The P-450IIIA family plays a significant role in metabolizing various drugs and endogenous compounds.
- Understanding the specific P-450 isoforms and their regulation is vital for drug development and personalized medicine.
Purpose of the Study:
- To isolate and characterize the full-length cDNA of a mouse P-450IIIA family member, designated P-450IIIM1.
- To determine the amino acid sequence of P-450IIIM1 and compare it to related rat and mouse P-450 proteins.
- To investigate the effect of dexamethasone on the expression of P-450IIIM1 mRNA in mouse liver.
Main Methods:
- Isolation and complete sequencing of a full-length cDNA clone (pMDex13) from mouse liver mRNA.
- Deduction of the amino acid sequence and comparison with homologous proteins using sequence identity analysis.
- RNA blot analysis to quantify hepatic P-450IIIM1 mRNA levels following dexamethasone treatment.
Main Results:
- A cDNA clone, pMDex13, was isolated and sequenced, encoding a 504-amino acid polypeptide (P-450IIIM1).
- The deduced amino acid sequence exhibited high identity (87.3% and 84.9%) with rat P-450IIIA1 and P-450IIIA2, respectively.
- NH2-terminal sequences of P-450IIIM1 were identical to purified mouse P-450UT protein.
- Dexamethasone treatment significantly increased the mRNA content of hepatic P-450IIIM1.
Conclusions:
- The study successfully identified and sequenced a novel mouse cytochrome P-450 gene, P-450IIIM1, belonging to the P-450IIIA family.
- P-450IIIM1 shares significant homology with rat P-450IIIA isoforms and is identical to mouse P-450UT at the N-terminus.
- Hepatic expression of P-450IIIM1 is inducible by dexamethasone, highlighting its potential role in drug metabolism and response.