OBJECTIVE: Most animals experience fasting-feeding cycles throughout their lives. It is well known that the liver plays a central role in regulating glycogen metabolism. However, how hepatic glycogenesis is coordinated with the fasting-feeding cycle to control postprandial @entity413 homeostasis remains largely unknown. This study determines the molecular mechanism underlying the coupling of hepatic glycogenesis with the fasting-feeding cycle. RESEARCH DESIGN AND METHODS: Through a series of molecular, cellular, and animal studies, we investigated how @entity70283 , a glycogen-targeting regulatory subunit of protein phosphatase 1 ( @entity27863 ), is implicated in regulating hepatic glycogenesis and @entity413 homeostasis in a manner tightly orchestrated with the fasting-feeding cycle. RESULTS: @entity70283 in the liver is upregulated during fasting and downregulated after feeding. @entity70283 associates with glycogen pellet, interacts with the catalytic subunit of @entity27863 , and regulates glycogen synthase (GS) activity. Fasting @entity413 level is reduced when @entity70283 is overexpressed in the liver. Hepatic knockdown of @entity70283 reduces postprandial elevation of GS activity, decreases postprandial accumulation of liver glycogen, and decelerates postprandial clearance of blood @entity413 . Other glycogen-targeting regulatory subunits of @entity27863 , such as @entity50261 , @entity4278 , and @entity70284 , are downregulated by fasting and increased by feeding in the liver. CONCLUSIONS: We propose that the opposite expression pattern of @entity70283 versus other @entity27863 regulatory subunits comprise an intricate regulatory machinery to control hepatic glycogenesis during the fasting-feeding cycle. Because of its unique expression pattern, @entity70283 plays a major role to control postprandial @entity413 homeostasis during the fasting-feeding transition via its regulation on liver glycogenesis.

Fasting-induced protein phosphatase 1 regulatory subunit contributes to postprandial blood XXXX homeostasis via regulation of hepatic glycogenesis.

@entity4278 :: ('5507', 'Gene') :: ['PPP1R3C'] @entity27863 :: ('5540', 'Gene') :: ['PP1'] @entity70284 :: ('5509', 'Gene') :: ['PPP1R3D'] @entity50261 :: ('79660', 'Gene') :: ['PPP1R3B'] @entity70283 :: ('648791', 'Gene') :: ['PPP1R3G'] @entity413 :: ('MESH:D005947', 'Chemical') :: ['glucose']
@entity413 :: (MESH:D005947,Chemical) :: ['glucose']
