PDF(Pubmed)
Abstract：
Lysosomes are dynamic cellular structures that adaptively remodel their membrane in response to stimuli, including membrane damage. We previously uncovered a process we term LYTL (LYsosomal Tubulation/sorting driven by Leucine-Rich Repeat Kinase 2 [LRRK2]), wherein damaged lysosomes generate tubules sorted into mobile vesicles. LYTL is orchestrated by the Parkinson\'s disease-associated kinase LRRK2 that recruits the motor adaptor protein and RHD family member JIP4 to lysosomes via phosphorylated RAB proteins. To identify new players involved in LYTL, we performed unbiased proteomics on isolated lysosomes after LRRK2 kinase inhibition. Our results demonstrate that there is recruitment of RILPL1 to ruptured lysosomes via LRRK2 activity to promote phosphorylation of RAB proteins at the lysosomal surface. RILPL1, which is also a member of the RHD family, enhances the clustering of LRRK2-positive lysosomes in the perinuclear area and causes retraction of LYTL tubules, in contrast to JIP4 which promotes LYTL tubule extension. Mechanistically, RILPL1 binds to p150Glued, a dynactin subunit, facilitating the transport of lysosomes and tubules to the minus end of microtubules. Further characterization of the tubulation process revealed that LYTL tubules move along tyrosinated microtubules, with tubulin tyrosination proving essential for tubule elongation. In summary, our findings emphasize the dynamic regulation of LYTL tubules by two distinct RHD proteins and pRAB effectors, serving as opposing motor adaptor proteins: JIP4, promoting tubulation via kinesin, and RILPL1, facilitating tubule retraction through dynein/dynactin. We infer that the two opposing processes generate a metastable lysosomal membrane deformation that facilitates dynamic tubulation events.
摘要：
溶酶体是动态的细胞结构，可以响应刺激自适应地重塑其膜，包括膜损坏。我们之前发现了一个过程，我们称之为LYTL（由富含亮氨酸的重复激酶2[LRRK2]驱动的溶酶体导管/分选），其中受损的溶酶体产生分选成移动囊泡的小管。LYTL由帕金森病相关激酶LRRK2协调，该激酶通过磷酸化RAB蛋白将运动衔接蛋白和RHD家族成员JIP4募集到溶酶体。为了确定参与LYTL的新玩家，我们对LRRK2激酶抑制后分离的溶酶体进行了无偏倚的蛋白质组学。我们的结果表明，RILPL1通过LRRK2活性募集到破裂的溶酶体中，以促进溶酶体表面RAB蛋白的磷酸化。RILPL1，也是RHD家族的成员，增强了LRRK2阳性溶酶体在核周区域的聚集，并导致LYTL小管的收缩，与促进LYTL小管延伸的JIP4相反。机械上,RILPL1结合p150胶合，一个动态肌动蛋白亚基，促进溶酶体和小管运输到微管的负端。对插管过程的进一步表征表明，LYTL小管沿着酪氨酸微管移动，微管蛋白酪氨酸化被证明是小管伸长所必需的。总之,我们的发现强调了两种不同的RHD蛋白和pRAB效应子对LYTL小管的动态调节，作为相反的运动衔接蛋白：JIP4，通过驱动蛋白促进输卵管，和RILPL1，通过动力蛋白/动力蛋白促进小管收缩。我们推断，这两个相反的过程会产生亚稳态的溶酶体膜变形，从而促进动态插管事件。
