title: Dissecting the nanoscale distributions and functions of microtubule-end-binding proteins EB1 and ch-TOG in interphase HeLa cells.
abstract: Recently, the EB1 and XMAP215/TOG families of microtubule binding proteins have been demonstrated to bind autonomously to the growing plus ends of microtubules and regulate their behaviour in in vitro systems. However, their functional redundancy or difference in cells remains obscure. Here, we compared the nanoscale distributions of EB1 and ch-TOG along microtubules using high-resolution microscopy techniques, and also their roles in microtubule organisation in interphase HeLa cells. The ch-TOG accumulation sites protruded ∼100 nm from the EB1 comets. Overexpression experiments showed that ch-TOG and EB1 did not interfere with each other's localisation, confirming that they recognise distinct regions at the ends of microtubules. While both EB1 and ch-TOG showed similar effects on microtubule plus end dynamics and additively increased microtubule dynamicity, only EB1 exhibited microtubule-cell cortex attachment activity. These observations indicate that EB1 and ch-TOG regulate microtubule organisation differently via distinct regions in the plus ends of microtubules.
authors.affiliation: Optical Image Analysis Unit, RIKEN Center for Developmental Biology, Kobe, Hyogo, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Nakamura
authors.forename: Ilya
authors.initials: I
authors.lastname: Grigoriev
authors.forename: Taisaku
authors.initials: T
authors.lastname: Nogi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hamaji
authors.forename: Lynne
authors.initials: L
authors.lastname: Cassimeris
authors.forename: Yuko
authors.initials: Y
authors.lastname: Mimori-Kiyosue
mesh_terms: D000906:Antibodies / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007399:Interphase; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D053758:Nanoparticles / Q000737:chemistry*; D021381:Protein Transport; D013194:Staining and Labeling; D014404:Tubulin / Q000378:metabolism
chemical_list: D000906:Antibodies; C454180:CKAP5 protein, human; C497850:CLASP1 protein, human; C405804:EB1 microtubule binding proteins; D005456:Fluorescent Dyes; D008869:Microtubule-Associated Proteins; C561112:SLAIN2 protein, human; D014404:Tubulin