Cytochromes b561: ascorbate-mediated trans-membrane electron transport

Asard, H. and Barbaro, R. and Trost, P. and Bérczi, Alajos (2013) Cytochromes b561: ascorbate-mediated trans-membrane electron transport. ANTIOXIDANTS AND REDOX SIGNALING. ISSN 1523-0864

[img] Text
ARS-Review-2013_repository version.pdf
Restricted to Registered users only

Download (1MB) | Request a copy


Significance: Cytochromes b561 (CYB561s) constitute a family of trans-membrane (TM), di-heme proteins, occurring in a variety of organs and cell types, in plants and animals, and using ascorbate (ASC) as an electron donor. CYB561s function as monodehydroascorbate (MDHA) reductase, regenerating ASC, and as Fe3+-reductases, providing reduced iron for TM transport. A CYB561-core domain is also associated with DOMON redox domains in ubiquitous CYBDOM proteins. In plants, CYBDOMs form large protein families. Physiological functions supported by CYB561s and CYBDOMs, include stress defense, cell wall modifications, iron metabolism, tumor suppression, and various neurological processes, including memory retention. CYB561s therefore significantly broaden our view on the physiological roles of ASC. Recent advances: the ubiquitous nature of CYB561s is only recently being recognized. Significant advances have been made through the study of recombinant CYB561s, revealing structural and functional properties of a unique "two-heme four-helix" protein configuration. In addition, the DOMON domains of CYBDOMs are suggested to contain another heme b. Critical Issues: new CYB561 proteins are still being identified, and there is a need to provide an insight and overview on the various roles of these proteins, and their structural properties. Future directions: mutant studies will reveal in more detail the mechanisms by which CYB561s and CYBDOMs participate in cell metabolism in plants and animals. Moreover, the availability of efficient heterologous expression systems should allow protein crystallization, more detailed (atomic-level) structural information and insight in the intra-molecular mechanism of electron transport.

Item Type: Article
Subjects: Q Science / természettudomány > QC Physics / fizika
Q Science / természettudomány > QH Natural history / természetrajz > QH301 Biology / biológia > QH3020 Biophysics / biofizika
Depositing User: MTMT SWORD
Date Deposited: 07 Aug 2013 09:49
Last Modified: 07 Aug 2013 09:49

Actions (login required)

Edit Item Edit Item