2012年5月8日的Nature Communications上的一項研究描述了一個6基因的新家族,,該新家族的功能是調節(jié)神經元中線粒體的運動與位置,。許多神經性疾病,,包括帕金森氏病和各種夏科-馬里-圖思?。–harcot-Marie-Tooth disease),都是由于控制線粒體轉運的基因改變而引起的,,其中線粒體轉運是一個給細胞功能提供必需能量的過程,。
這一研究指出了線粒體生物學的相關性,隨著大腦大小,、功能和結構的進化,,線粒體轉運過程變得更復雜,也可能需要另外的調節(jié)機制,。正確的大腦功能是高度耗能的,,然而,這種能量必須被精細地分布到整個神經元,,這些神經元就是一些有分支的細胞,,其分支可從大腦延伸到四肢,長達數厘米,。這組基因形成線粒體的"輪子"機制部分,,根據每個細胞的能量需求來調節(jié)它們的定位,就象細胞內線粒體運輸的額外控制一樣,,還與線粒體運輸調節(jié)相關的主要蛋白相互作用,。
這些新蛋白還有另一個驚人特點,即它們既存在于線粒體內也存在于細胞核內,,但現在還不清楚它們在細胞核內的功能,,可能涉及到基因表達的調節(jié)。除了涉及大腦病理之外,,這些蛋白也可能與代謝性疾病和癌癥有關,。(生物谷bioon.com)
doi:10.1038/ncomms1829
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The Eutherian Armcx genes regulate mitochondrial trafficking in neurons and interact with Miro and Trak2
Guillermo López-Doménech, Román Serrat, Serena Mirra, Salvatore D'Aniello, Ildiko Somorjai, Alba Abad, Nathalia Vitureira, Elena García-Arumí, María Teresa Alonso, Macarena Rodriguez-Prados, Ferran Burgaya, Antoni L. Andreu, Javier García-Sancho, Ramón Trullas, Jordi Garcia-Fernàndez, Eduardo Soriano
Brain function requires neuronal activity-dependent energy consumption. Neuronal energy supply is controlled by molecular mechanisms that regulate mitochondrial dynamics, including Kinesin motors and Mitofusins, Miro1-2 and Trak2 proteins. Here we show a new protein family that localizes to the mitochondria and controls mitochondrial dynamics. This family of proteins is encoded by an array of armadillo (Arm) repeat-containing genes located on the X chromosome. The Armcx cluster is unique to Eutherian mammals and evolved from a single ancestor gene (Armc10). We show that these genes are highly expressed in the developing and adult nervous system. Furthermore, we demonstrate that Armcx3 expression levels regulate mitochondrial dynamics and trafficking in neurons, and that Alex3interacts with the Kinesin/Miro/Trak2 complex in a Ca2+-dependent manner. Our data provide evidence of a new Eutherian-specific family of mitochondrial proteins that controls mitochondrial dynamics and indicate that this key process is differentially regulated in the brain of higher vertebrates.