Nonerythroid alphaII spectrin is required for recruitment of FANCA and XPF to nuclear foci induced by DNA interstrand cross-links.

Abstract

The events responsible for repair of DNA interstrand cross-links in mammalian cells, the proteins involved and their interactions with each other are poorly understood. The present study demonstrates that the structural protein nonerythroid alpha spectrin (alphaSpIISigma*), present in normal human cell nuclei, plays an important role in repair of DNA interstrand cross-links. These results show that alphaSpIISigma* relocalizes to nuclear foci after damage of normal human cells with the DNA interstrand cross-linking agent 8-methoxypsoralen plus ultraviolet A (UVA) light and that FANCA and the known DNA repair protein XPF localize to the same nuclear foci. That alphaSpIISigma* is essential for this re-localization is demonstrated by the finding that in cells from patients with Fanconi anemia complementation group A (FA-A), which have decreased ability to repair DNA interstrand cross-links and decreased levels of alphaSpIISigma*, there is a significant reduction in formation of damage-induced XPF as well as alphaSpIISigma* nuclear foci, even though levels of XPF are normal in these cells. In corrected FA-A cells, in which levels of alphaSpIISigma* are restored to normal, numbers of damage-induced nuclear foci are also returned to normal. Co-immunoprecipitation studies show that alphaSpIISigma*, FANCA and XPF co-immunoprecipitate with each other from normal human nuclear proteins. These results demonstrate that alphaSpIISigma*, FANCA and XPF interact with each other in the nucleus and indicate that there is a close functional relationship between these proteins. These studies suggest that an important role for alphaSpIISigma* in the nucleus is to act as a scaffold, aiding in recruitment and alignment of repair proteins at sites of damage.

• Authors: Deepa Sridharan, Monique Brown, W Clark Lambert, Laura W McMahon, Muriel W Lambert
• Journal: Journal of cell science (J Cell Sci) Vol. 116 Issue Pt 5 Pg. 823-35 (Mar 01 2003) ISSN: 0021-9533 [Print] England
• PMID: 12571280 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Cross-Linking Reagents
• DNA Adducts
• DNA-Binding Proteins
• FANCA protein, human
• Fanconi Anemia Complementation Group A Protein
• Nuclear Proteins
• Proteins
• xeroderma pigmentosum group F protein
• Spectrin
• Methoxsalen

Topics

• Blotting, Western
• Cell Line
• Cell Nucleus (drug effects, metabolism, radiation effects)
• Cross-Linking Reagents (pharmacology)
• DNA Adducts (metabolism)
• DNA Damage
• DNA Repair
• DNA-Binding Proteins (metabolism)
• Dose-Response Relationship, Radiation
• Fanconi Anemia Complementation Group A Protein
• Fluorescent Antibody Technique, Indirect
• Humans
• Methoxsalen (pharmacology)
• Nuclear Proteins (metabolism)
• Precipitin Tests (methods)
• Proteins (metabolism)
• Spectrin (metabolism)
• Time Factors
• Ultraviolet Rays