Jaw1/LRMP is associated with the maintenance of Golgi ribbon structure

Abstract

Jaw1/LRMP is a membrane protein that is localized to the endoplasmic reticulum and outer nuclear membrane. Previously, we revealed that Jaw1 functions to maintain nuclear shape by interacting with microtubules as a Klarsicht/ANC-1/Syne/homology (KASH) protein. The loss of several KASH proteins causes defects in the position and shape of the Golgi apparatus as well as the nucleus, but the effects of Jaw1 depletion on the Golgi apparatus were poorly understood. Here, we found that siRNA-mediated Jaw1 depletion causes Golgi fragmentation with disordered ribbon structure in the melanoma cell, accompanied by the change in the localization of the Golgi-derived microtubule network. Thus, we suggest that Jaw1 is a novel protein to maintain the Golgi ribbon structure, associated with the microtubule network.

Keywords: Golgi apparatus.Abbreviations: Ac-Tubulin, Acetylated-Tubulin; CLASPs, CLIP-associated proteins; DNase I, Deoxyribonuclease I; ER, Endoplasmic reticulum; GM130, Golgi matrix protein 130 kDa; GRASP65, Golgi reassembly-stacking protein 1; GRASP55, Golgi reassembly-stacking protein 2; HRP, Horseradish peroxidase; ITPR, Inositol 1,4,5-trisphosphate receptor; KASH, Klarsicht/ANC-1/Syne/homology; KD, knockdown; KIF20A, Kinesin-like protein KIF20A; LINC, Linker of nucleus and cytoskeletons; LRMP, Lymphoid restricted membrane protein; MTCL1, Microtubule cross-linking factor 1; NT, Non-targeting; ONM, outer nuclear membrane; siRNA, short interfering RNA; SUN, Sad-1/UNC-84; TEM, transmission electron microscopy; Jaw1/LRMP; KASH protein; LINC complex; microtubule network.