Prolyl Isomerase Pin1 Negatively Regulates AMP-activated Protein Kinase (AMPK) by Associating with the CBS Domain in the γ Subunit

Yusuke Nakatsu,Misaki Iwashita,Hideyuki Sakoda,Hiraku Ono,Kengo Nagata,Yasuka Matsunaga,Toshiaki Fukushima,Midori Fujishiro,Akifumi Kushiyama,Hideaki Kamata,Shin-Ichiro Takahashi,Hideki Katagiri,Hiroaki Honda,Hiroshi Kiyonari,Takafumi Uchida,Tomoichiro Asano

doi:10.1074/jbc.m115.658559

Abstract

AMP-activated protein kinase (AMPK) plays a critical role in metabolic regulation. In this study, first, it was revealed that Pin1 associates with any isoform of γ, but not with either the α or the β subunit, of AMPK. The association between Pin1 and the AMPK γ1 subunit is mediated by the WW domain of Pin1 and the Thr(211)-Pro-containing motif located in the CBS domain of the γ1 subunit. Importantly, overexpression of Pin1 suppressed AMPK phosphorylation in response to either 2-deoxyglucose or biguanide stimulation, whereas Pin1 knockdown by siRNAs or treatment with Pin1 inhibitors enhanced it. The experiments using recombinant Pin1, AMPK, LKB1, and PP2C proteins revealed that the protective effect of AMP against PP2C-induced AMPKα subunit dephosphorylation was markedly suppressed by the addition of Pin1. In good agreement with the in vitro data, the level of AMPK phosphorylation as well as the expressions of mitochondria-related genes, such as PGC-1α, which are known to be positively regulated by AMPK, were markedly higher with reduced triglyceride accumulation in the muscles of Pin1 KO mice as compared with controls. These findings suggest that Pin1 plays an important role in the pathogenic mechanisms underlying impaired glucose and lipid metabolism, functioning as a negative regulator of AMPK.

Highlights

Pin1 expression is regulated by nutrient conditions
The experiments using recombinant Pin1, AMPK, LKB1, and PP2C proteins revealed that the protective effect of AMP against PP2C-induced AMPK␣ subunit dephosphorylation was markedly suppressed by the addition of Pin1
In good agreement with the in vitro data, the level of AMPK phosphorylation as well as the expressions of mitochondria-related genes, such as PGC-1␣, which are known to be positively regulated by AMPK, were markedly higher with reduced triglyceride accumulation in the muscles of Pin1 KO mice as compared with controls

Summary

Conclusion

In good agreement with the in vitro data, the level of AMPK phosphorylation as well as the expressions of mitochondria-related genes, such as PGC-1␣, which are known to be positively regulated by AMPK, were markedly higher with reduced triglyceride accumulation in the muscles of Pin KO mice as compared with controls These findings suggest that Pin plays an important role in the pathogenic mechanisms underlying impaired glucose and lipid metabolism, functioning as a negative regulator of AMPK. We present evidence showing that increased expression of Pin reduces the efficiency of AMPK phosphorylation This mechanism may be involved the pathogenesis of impaired lipid and glucose metabolism in diabetic and obese subjects

Experimental Procedures

Results

Discussion