Analysis of nuclear protein complexes comprising a-actinin-4 by 2D-electrophoresis and mass-spectrometry
2009 (English)In: Tsitologiya, ISSN 0041-3771, Vol. 51, no 8, 684-690 p.Article in journal (Refereed) Published
Actin-binding protein a-actinin-4 is a member of spectrin super family. It is located in the cytoplasm and in the nucleus. However, nuclear functions of a-actinin-4 are still not clear. In this study, we analyzed composition of nuclear protein complexes associated with a-actinin-4 in A431 cells. Using 2D electrophoresis, we have determined that about 50 different proteins may be associated with nuclear a-actinin-4. Using mass-spectrometry, we analyzed major proteins of these complexes. ß-Actin, a- and ß-tubulins, ribonucleoprotein A2/B1, which regulates splicing and is associated with ß-actin, peroxiredoxin-1, which is involved in oxidative stress, and glycolytic enzyme D-3-phosphoglycerate dehydrogenase were identified by MALDI-TOF. Detection of these proteins in nuclear complexes with a-actinin-4 may suggest that a-actinin-4 is involved in transcription and splicing. Presence of a-actin in the investigated complexes was confirmed by tandem mass-spectrometry (MALDITOF-TOF). Immunoprecipitation of nuclear proteins with antibodies against a-tubulin confirmed association of a-actinin-4 with a-tubulin in the protein complex. Nuclear a-actinin-4 constitutes of 105 KDa fullsize isoform and two truncated isoforms of 65 and 75 kDa, whereas only the truncated isoform have been found in nuclear complexes with a-tubulin. These data suggest that a-actinin-4 is associated with a number of different nuclear protein complexes which may carry out different functions in the cell nucleus.
Place, publisher, year, edition, pages
SP MAIK Nauka/Interperiodica , 2009. Vol. 51, no 8, 684-690 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-57041DOI: 10.1134/S1990519X09050058OAI: oai:DiVA.org:liu-57041DiVA: diva2:323996