MilliporeSigma
  • The tight junction protein TJP1 regulates the feeding-modulated hepatic circadian clock.

The tight junction protein TJP1 regulates the feeding-modulated hepatic circadian clock.

Nature communications (2020-02-01)
Yi Liu, Yuanyuan Zhang, Tong Li, Jinbo Han, Yiguo Wang
ABSTRACT

Circadian clocks in the suprachiasmatic nucleus and peripheral tissues orchestrate behavioral and physiological activities of mammals in response to environmental cues. In the liver, the circadian clock is also modulated by feeding. However, the molecular mechanisms involved are unclear. Here, we show that TJP1 (tight junction protein 1) functions as a mediator of mTOR (mechanistic target of rapamycin) to modulate the hepatic circadian clock. TJP1 interacts with PER1 (period circadian regulator 1) and prevents its nuclear translocation. During feeding, mTOR phosphorylates TJP1 and attenuates its association with PER1, thereby enhancing nuclear shuttling of PER1 to dampen circadian oscillation. Therefore, our results provide a previously uncharacterized mechanistic insight into how feeding modulates the hepatic circadian clock.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
LookOut® Mycoplasma PCR Detection Kit, Optimized for use with JumpStart Taq DNA Polymerase, D9307.
Sigma-Aldrich
Monoclonal ANTI-FLAG® M2 antibody produced in mouse, 1 mg/mL, clone M2, affinity isolated antibody, buffered aqueous solution (50% glycerol, 10 mM sodium phosphate, and 150 mM NaCl, pH 7.4)
Sigma-Aldrich
Serum Triglyceride Determination Kit, 1 kit sufficient for 250 tests
Sigma-Aldrich
MEM Amino Acids (50x) solution, Without L-glutamine, liquid, sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Lysosome Isolation Kit, sufficient for 25 g (tissue), sufficient for 20 mL (packed cells), enrichment of lysosomes from tissues and packed cells
Sigma-Aldrich
Anti-ZO-1 Antibody, clone R40.76, clone R40.76, from rat
Sigma-Aldrich
Anti-α-Tubulin antibody, Mouse monoclonal, clone DM1A, purified from hybridoma cell culture
Sigma-Aldrich
Anti-LAMP1 antibody produced in rabbit, affinity isolated antibody, buffered aqueous solution