Effect of dietary protein manipulation on translocation of protein kinase C activity in various tissues of rats
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S K Bansal1, A S Jaiswal, R Kathayat
1Department of Biochemistry, V P Chest Institute, University of Delhi, India.
Abstract:
Ingestion of protein deficient diet is known to decrease the enzyme load, particularly drug metabolising enzymes in liver. It also leads to decrease in polyphosphoinositide pool in brain and kidney. Therefore, changes in protein kinase C activity and its translocation were speculated and studied in brain, lung, heart, spleen, liver and kidney of rats maintained on three different diets, viz. casein (20% protein) deficient (4% protein, rice flour as protein source) and supplemented (deficient diet supplemented with L-lysine and DL-threonine), for 28 days. A significant alteration in total protein kinase C activity and/or its translocation was observed in these tissues in the deficient group in comparison to casein group. Supplementation of diet with L-lysine and DL-threonine could partially reverse the affect. These changes in protein kinase C activity and its translocation indicate alteration in the mechanism of signalling system in dietary protein deficiency and hence an altered response of tissues to the external stimuli in dietary protein deficiency.
Insights
Dietary protein deficiency significantly alters protein kinase C activity and its signaling pathways in rat tissues. Supplementing with L-lysine and DL-threonine partially reverses these effects, indicating a role in mitigating deficiency impacts.
Area of Science:
- Biochemistry
- Nutrition Science
- Physiology
Background:
- Dietary protein deficiency reduces liver enzyme activity, including drug-metabolizing enzymes.
- A low protein diet depletes the polyphosphoinositide pool in the brain and kidney.
- Protein kinase C (PKC) plays a crucial role in cellular signaling pathways.
Purpose of the Study:
- To investigate the impact of dietary protein deficiency on protein kinase C (PKC) activity and translocation.
- To examine the effects of specific amino acid supplementation on PKC alterations.
- To understand the consequences for cellular signaling and tissue response.
Main Methods:
- Rats were fed casein (20% protein), protein-deficient (4% protein), or supplemented (deficient + L-lysine/DL-threonine) diets for 28 days.
- Protein kinase C activity and translocation were measured in brain, lung, heart, spleen, liver, and kidney.
- Comparative analysis was performed between dietary groups.
Main Results:
- Protein-deficient diets caused significant alterations in total protein kinase C activity and/or its translocation across multiple tissues.
- These changes were observed when comparing the deficient group to the control casein group.
- Dietary supplementation with L-lysine and DL-threonine partially reversed the observed effects on PKC.
Conclusions:
- Dietary protein deficiency disrupts cellular signaling mechanisms involving protein kinase C.
- PKC alterations suggest an impaired tissue response to external stimuli under protein-deficient conditions.
- Amino acid supplementation shows potential in mitigating the negative impacts of protein deficiency on cellular signaling.