Nuclear localization of SNARK; its impact on gene expression.
SNARK, a member of the AMPK-related kinases, has been involved in the cellular stress responses but its precise mechanisms remain unclear. Subcellular localization of SNARK protein was identified. Unlike cytoplasmic localizing AMPKalpha, SNARK was predominantly localized in the nucleus. SNARK was constitutively distributed in the nucleus even when SNARK was activated by metabolic stimuli such as AICAR and glucose-deprivation. Conserved nuclear localization signal (NLS) was identified at the N-terminal portion ((68)KKAR(71)). Deletion and point mutation of this part resulted in the cytoplasmic translocation of mutant proteins. Furthermore, GFP fused with the SNARK fragment containing (68)KKAR(71) translocated to the nucleus. A microarray analysis revealed that the nuclear localizing SNARK altered transcriptome profiles and a considerable part of these alterations were canceled by the mutation of NLS, suggesting the ability of SNARK to modulate gene expression dependent on its nuclear localization.
Kuga
Wataru
W
Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan.
Tsuchihara
Katsuya
K
Ogura
Tsutomu
T
Kanehara
Sakyo
S
Saito
Marie
M
Suzuki
Atsushi
A
Esumi
Hiroyasu
H
D021581:Active Transport, Cell Nucleus; D002467:Cell Nucleus / Q000201:enzymology*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D009154:Mutation; D019913:Nuclear Localization Signals / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
D019913:Nuclear Localization Signals; D049452:Green Fluorescent Proteins; C486061:NUAK2 protein, human; D017346:Protein Serine-Threonine Kinases