Role of the salt bridge between glutamate 546 and arginine 907 in preservation of autoinhibited form of Apaf-1
2015 (English)In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 81, 370-374 p.Article in journal (Refereed) PublishedText
Apaf-1, the key element of apoptotic mitochondrial pathway, normally exists in an auto-inhibited form inside the cytosol. WRD-domain of Apaf-1 has a critical role in the preservation of auto-inhibited form; however the underlying mechanism is unclear. It seems the salt bridges between WRD and NOD domains are involved in maintaining the inactive conformation of Apaf-1. At the present study, we have investigated the effect of E546-R907 salt bridge on the maintenance of auto-inhibited form of human Apaf-1. E546 is mutated to glutamine (Q) and arginine (R). Over-expression of wild type Apaf-1 and its E546Q and E546R variants in HEK293T cells does not induce apoptosis unlike - HL-60 cancer cell line. In vitro apoptosome formation assay showed that all variants are cytochrome c and dATP dependent to form apoptosome and activate endogenous procaspase-9 in Apaf-1-knockout MEF cell line. These results suggest that E546 is not a critical residue for preservation of auto-inhibited Apaf-1. Furthermore, the behavior of Apaf-1 variants for in vitro apoptosome formation in HEK293T cell is similar to exogenous wild type Apaf-1. Wild type and its variants can form apoptosome in HEK293T cell with different procaspase-3 processing pattern in the presence and absence of exogenous cytochrome c and dATP. (C) 2015 Elsevier B.V. All rights reserved.
Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV , 2015. Vol. 81, 370-374 p.
Apaf-1; Apoptosome; Caspase-9
Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)
IdentifiersURN: urn:nbn:se:liu:diva-124522DOI: 10.1016/j.ijbiomac.2015.08.027ISI: 000367408300045PubMedID: 26277751OAI: oai:DiVA.org:liu-124522DiVA: diva2:899509
Funding Agencies|Research Council of University of Tehran; Tarbiat Modares University; Linkoping University; Integrative Regenerative Medicine Center (IGEN); Cancerfonden [2013/391]; VR-NanoVision [K2012-99X-22325-01-5]2016-02-022016-02-012016-04-25