Related Experiment Video
Updated: Jun 18, 2026

Methods to Study Mrp4-containing Macromolecular Complexes in the Regulation of Fibroblast Migration
Published on: May 19, 2016
TYR-MIF-1, but not MIF-1 or morphine, decreases cyclic AMP-dependent protein kinase activity extracted from HeLa
X Y Zhang1, J E Zadinat, M Ehrlich
1Department of Biochemistry, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
Abstract:
The biochemical effects of Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH(2)), a naturally occurring opiate modulator, on cellular function are poorly understood. We looked for changes in cyclic AMP-dependent protein kinase (cAMP-kinase; protein kinase A) after treating HeLa cells with this peptide. Binding sites for Tyr-MIF-1 (IC(50) = 83 nM), but not for DAMGO, a mu opiate, were found on these cells. Brief incubation of HeLa cells with 10(-7) to 10(-5)M Tyr-MIF-1 significantly decreased, in a rapid and dose-dependent manner, cAMP-kinase activity in cell extracts assayed in reaction mixtures with added cAMP but not the much lower basal enzymatic activity that is dependent on endogenous cAMP. In contrast, incubation of the cells with the related peptide MIF-1 (Pro-Leu-Gly-NH(2)) or with morphine did not significantly alter cAMP-kinase activity. This study shows that Tyr-MIF-1 can affect part of a major signal transduction pathway independently of binding to opiate receptors.
More Related Videos
15:43Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes
Published on: January 7, 2013
09:18Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
Published on: December 27, 2016
Related Concept Videos
Amplifying Signals via Enzymatic Cascade
cAMP-dependent Protein Kinase Pathways
MAPK Signaling Cascades
Mitogens and the Cell Cycle
GPCRs Regulate Adenylyl Cylase Activity
Two...
Amplifying Signals via Second Messengers