CEP295 interacts with microtubules and is required for centriole elongation (Journal of Cell Science 2016, 129:2501-2513)

報告日期: 2016/11/22
報告時間: 5:10/6:00
報告學生: 陳亭羽
講評老師: 鄭宏祺
附件下載: 下載[1602-1473728351-1.pdf] 

CEP295 interacts with microtubules and is required for centriole elongation

Ching-Wen Chang, Wen-Bin Hsu, Jhih-Jie Tsai, Chieh-Ju C. Tang and

Tang K. Tang*

Journal of Cell Science (2016) 129, 2501-2513

Speaker :Ting-Yu Chen 陳亭羽  Commentator: Prof. Hung-Chi Cheng 鄭宏祺老師

Date: 2016/11/22 17:10-18:00   Location: Room 602

Abstract

Centrioles are called microtubule-organizing center (MTOC) and build cell skeleton which are important for many cellular processes. It has been known the aberrant processes of centriole duplication lead many human diseases such as cancer, brain diseases and ciliopathy. Centriole duplication includes three steps: initiation, elongation and maturation. It is reported procentrioles are assembled during G1/S transition and elongate at late S and G2 phase. Centriole duplication includes three types: (1) the orthogonal type, in which daughter centriole forms orthogonal to mother centriole; (2) the rosette type, in which multiple procentriole assemble around the pother centriole; (3) the ectopic orthogonal type: in which numerous procentrioles form orthogonal to pre-existing centriole. Recent studies have detected numerous proteins including PLK4, SAS6, STIL, CEP135 CPAP and CEP120, which are required for initial cartwheel formation and procentriole elongation during centriole duplication. However, the molecular mechanism of late centriole elongation remains obscure. CEP295 (Drosophila Ana1) is known for regulating centriole duplication in interphase and required for centriole-centrosome conversion in mitosis. However, the role of CEP295-regulated centriole duplication is not clear. Here, the authors prove depletion of CEP295 induced the shorten centrioles at the late S and G2 phase. They found CEP295 directly interacts with centriole wall and microtubule via the ALMS functional domain of CEP295. CEP295 is also located to the proximal end of centrioles and regulates the post-translational modification including acetylation and glutamylation to stabilize the centriole microtubules by using super-resolution and immunogold electron microscopy. In addition, CEP295 inhibits the recruitment of POC5 and POC1B to the distal ends of procentriole which are essential for controlling the centriole length. During centriole elongation, CPAP and CEP135 play a role to the recruitment of CEP295 to centrioles. It seems CPAP and CEP135 are the upstream regulators of CEP295 recruitment. However, they found excess CEP295 induce overly long centriole with low efficiency. According to these data, they suggest CEP295 is important for building the distal half centrioles and regulating post-translational modification of microtubules during centriole elongation.