| First Author | Chen YB | Year | 2011 |
| Journal | J Cell Biol | Volume | 195 |
| Issue | 2 | Pages | 263-76 |
| PubMed ID | 21987637 | Mgi Jnum | J:177718 |
| Mgi Id | MGI:5295894 | Doi | 10.1083/jcb.201108059 |
| Citation | Chen YB, et al. (2011) Bcl-xL regulates mitochondrial energetics by stabilizing the inner membrane potential. J Cell Biol 195(2):263-76 |
| abstractText | Mammalian Bcl-x(L) protein localizes to the outer mitochondrial membrane, where it inhibits apoptosis by binding Bax and inhibiting Bax-induced outer membrane permeabilization. Contrary to expectation, we found by electron microscopy and biochemical approaches that endogenous Bcl-x(L) also localized to inner mitochondrial cristae. Two-photon microscopy of cultured neurons revealed large fluctuations in inner mitochondrial membrane potential when Bcl-x(L) was genetically deleted or pharmacologically inhibited, indicating increased total ion flux into and out of mitochondria. Computational, biochemical, and genetic evidence indicated that Bcl-x(L) reduces futile ion flux across the inner mitochondrial membrane to prevent a wasteful drain on cellular resources, thereby preventing an energetic crisis during stress. Given that F(1)F(O)-ATP synthase directly affects mitochondrial membrane potential and having identified the mitochondrial ATP synthase beta subunit in a screen for Bcl-x(L)-binding partners, we tested and found that Bcl-x(L) failed to protect beta subunit-deficient yeast. Thus, by bolstering mitochondrial energetic capacity, Bcl-x(L) may contribute importantly to cell survival independently of other Bcl-2 family proteins. |
