TY - JOUR
T1 - GAK, a regulator of clathrin-mediated membrane trafficking, localizes not only in the cytoplasm but also in the nucleus
AU - Sato, Jun
AU - Shimizu, Hiroyuki
AU - Kasama, Takashi
AU - Yabuta, Norikazu
AU - Nojima, Hiroshi
PY - 2009
Y1 - 2009
N2 - The ubiquitously expressed Cyclin G-associated kinase (GAK) regulates clathrin-mediated membrane trafficking in the cytoplasm. However, the association of GAK with a nuclear protein Cyclin G1 that is unrelated to membrane trafficking suggests an unidentified role of GAK in the nucleus. Indeed, we report here that GAK localizes in both cytoplasm and nucleus by immunostaining, ectopic expression of GFP-GAK and pull-down assays using dissected GAK fragments. GAK forms complexes not only with cyclin G1 but also with other nuclear proteins such as p53, clathrin heavy chain (CHC) and protein phosphatase 2A (PP2A) B′α1. Moreover, CHC associates with GAK via a different domain depending on whether it is in the cytoplasm or nucleus. Immunostaining revealed that about 20∼30% of B′α1, cyclin G1 and p53 complex with nuclear GAK. CHC also displayed dots in the nucleus and almost all nuclear CHC signals colocalized with GAK. These observations together suggest an important function of GAK in the nucleus.
AB - The ubiquitously expressed Cyclin G-associated kinase (GAK) regulates clathrin-mediated membrane trafficking in the cytoplasm. However, the association of GAK with a nuclear protein Cyclin G1 that is unrelated to membrane trafficking suggests an unidentified role of GAK in the nucleus. Indeed, we report here that GAK localizes in both cytoplasm and nucleus by immunostaining, ectopic expression of GFP-GAK and pull-down assays using dissected GAK fragments. GAK forms complexes not only with cyclin G1 but also with other nuclear proteins such as p53, clathrin heavy chain (CHC) and protein phosphatase 2A (PP2A) B′α1. Moreover, CHC associates with GAK via a different domain depending on whether it is in the cytoplasm or nucleus. Immunostaining revealed that about 20∼30% of B′α1, cyclin G1 and p53 complex with nuclear GAK. CHC also displayed dots in the nucleus and almost all nuclear CHC signals colocalized with GAK. These observations together suggest an important function of GAK in the nucleus.
UR - http://www.scopus.com/inward/record.url?scp=65449137085&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=65449137085&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2443.2009.01296.x
DO - 10.1111/j.1365-2443.2009.01296.x
M3 - Article
C2 - 19371378
AN - SCOPUS:65449137085
SN - 1356-9597
VL - 14
SP - 627
EP - 641
JO - Genes to Cells
JF - Genes to Cells
IS - 5
ER -