title: Bcl-2 proteins EGL-1 and CED-9 do not regulate mitochondrial fission or fusion in Caenorhabditis elegans.
abstract: The Bcl-2 family proteins are critical apoptosis regulators that associate with mitochondria and control the activation of caspases. Recently, both mammalian and C. elegans Bcl-2 proteins have been implicated in controlling mitochondrial fusion and fission processes in both living and apoptotic cells. To better understand the potential roles of Bcl-2 family proteins in regulating mitochondrial dynamics, we carried out a detailed analysis of mitochondria in animals that either lose or have increased activity of egl-1 and ced-9, two Bcl-2 family genes that induce and inhibit apoptosis in C. elegans, respectively. Unexpectedly, we found that loss of egl-1 or ced-9, or overexpression of their gene products, had no apparent effect on mitochondrial connectivity or mitochondrial size. Moreover, loss of ced-9 did not affect the mitochondrial morphology observed in a drp-1 mutant, in which mitochondrial fusion occurs but mitochondrial fission is defective, or in a fzo-1 mutant, in which mitochondrial fission occurs but mitochondrial fusion is restricted, suggesting that ced-9 is not required for either the mitochondrial fission or fusion process in C. elegans. Taken together, our results argue against an evolutionarily conserved role for Bcl-2 proteins in regulating mitochondrial fission and fusion.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA. breckenridge.david@gmail.com
authors.forename: David G
authors.initials: DG
authors.lastname: Breckenridge
authors.forename: Byung-Ho
authors.initials: BH
authors.lastname: Kang
authors.forename: Ding
authors.initials: D
authors.lastname: Xue