[Frontiers in Bioscience 12, 1041-1048, January 1, 2007]

The biological significance of mtNOS modulation

María C. Carreras 1,2, María C. Franco 1, Paola V. Finocchietto 1,3, Daniela P. Converso 1, Valeria G. Antico Arciuch1, Silvia Holod1,2, Jorge G. Peralta1,3 and Juan J. Poderoso 1,3

1 Laboratory of Oxygen Metabolism and 2 Departments of Clinical Biochemistry, and 3 Medicine, University Hospital, University of Buenos Aires, Buenos Aires, Argentina

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. nNOS translocation to mitochondria: the mtNOS
4. Adaptation to O2 levels
5. Adaptation to environment
6. Endocrine regulation
7. mtNOS modulation in development
8. Brain synaptic plasticity
9. Conclusions and Perspectives
10. Acknowledgments
11. References

1. ABSTRACT

In the last years, nitric oxide synthases (NOS) have been localized in mitochondria. At this site, NO yield directly regulates the activity of cytochrome oxidase, O(2) uptake and the production of reactive oxygen species. Recent studies showed that translocated neuronal nitric oxide synthase (nNOS) is posttranslationally modified including phosphorylation at Ser 1412 (in mice) and myristoylation in an internal residue. Different studies confirm that modified nNOS alpha is the main modulable isoform in mitochondria. Modulation of mtNOS was observed in different situations, like adaptation to reduced O(2) availability and hypoxia, adaptation to low environmental temperature, and processes linked to life and death by effects on kinases and transcription factors. We present here evidence about the role of mtNOS in the analyzed conditions.