The mechanochemical GTPase dynamin-related protein 1 (Drp1) catalyzes mitochondrial and peroxisomal fission, but the regulatory mechanisms remain ambiguous. Here we find that a conserved, intrinsically disordered, six-residue Short Linear Motif at the extreme Drp1 C-terminus, named CT-SLiM, constitutes a critical allosteric site that controls Drp1 structure and function in vitro and in vivo. Extension of the CT-SLiM by non-native residues, or its interaction with the protein partner GIPC-1, constrains Drp1 subunit conformational dynamics, alters self-assembly properties, and limits cooperative GTP hydrolysis, surprisingly leading to the fission of model membranes in vitro. In vivo, the involvement of the native CT-SLiM is critical for productive mitochondrial and peroxisomal fission, as both deletion and non-native extension of the CT-SLiM severely impair their progression. Thus, contrary to prevailing models, Drp1-catalyzed membrane fission relies on allosteric communication mediated by the CT-SLiM, deceleration of GTPase activity, and coupled changes in subunit architecture and assembly-disassembly dynamics.

机械化学 GTP 酶动力蛋白相关蛋白 1 （Drp1） 催化线粒体和过氧化物酶体裂变，但调节机制仍然不明确。在这里，我们发现在极端 Drp1 C 末端的一个保守的、本质上无序的、六残基的短线性基序，称为 CT-SLiM，构成了在体外和体内控制 Drp1 结构和功能的关键变构位点。CT-SLiM 通过非天然残基的延伸，或其与蛋白质伴侣 GIPC-1 的相互作用，限制了 Drp1 亚基构象动力学，改变了自组装特性，并限制了协作 GTP 水解，令人惊讶地导致体外模型膜的裂变。在体内，天然 CT-SLiM 的参与对于生产性线粒体和过氧化物酶体裂变至关重要，因为 CT-SLiM 的缺失和非天然延伸都会严重损害它们的进展。因此，与主流模型相反，Drp1 催化的膜裂变依赖于 CT-SLiM 介导的变构通讯、GTP 酶活性的减速以及亚基结构和组装-拆卸动力学的耦合变化。