Related Experiment Videos
Microinjected Xenopus oocytes secrete mature, biologically active parathyroid hormone
K Ikeda1, J T Posillico, M B Boyle
1Department of Internal Medicine, Yale University, New Haven, Connecticut 06510.
Molecular Endocrinology (Baltimore, Md.)
|July 1, 1989
Summary
Xenopus oocytes can process preproparathyroid hormone (PTH) into mature PTH. This study demonstrates the oocyte
Area of Science:
- Molecular Biology
- Endocrinology
- Xenopus Oocyte Expression System
Background:
- Xenopus oocytes are utilized for heterologous protein expression and post-translational modification.
- Oocytes are known to perform many protein modifications but may struggle with specific two-step cleavages of propeptide intermediates.
Purpose of the Study:
- To investigate the capacity of Xenopus oocytes to process preproparathyroid hormone (PTH).
- To determine if oocytes can accurately cleave preproPTH into its mature, secreted form.
Main Methods:
- Microinjection of parathyroid mRNA into Xenopus oocytes.
- Detection of secreted PTH using a cytochemical bioassay.
- Characterization of secreted and intracellular PTH forms via immunoprecipitation and specific inhibitors.
Main Results:
- Microinjected oocytes secreted biologically active PTH.
- Secreted PTH activity was specifically blocked by PTH inhibitors, anti-PTH antiserum, and PTH-complementary oligonucleotides.
- Oocyte homogenates contained both proPTH and mature PTH, while the conditioned medium contained only mature PTH(1-84).
Conclusions:
- Xenopus oocytes can accurately process preproparathyroid hormone (PTH) into the mature, secreted peptide.
- This finding expands the known capabilities of the Xenopus oocyte expression system for complex protein maturation.