DIURNAL REGULATION OF HEPATIC PROTEIN PROCESSING AND SECRETION

The liver is a major regulator of homeostasis and physiology and acts as an endocrine organ secreting the majority of blood proteins. Dysregulations of hepatic protein secretion are implicated with pathophysiology. Thus, the understanding of the underlying mechanisms of how protein secretion is regulated is crucial. We have previously shown that protein secretion in mouse liver is diurnal. To further elucidate rhythmic protein secretion, we collected mouse liver samples over the course of the day and performed a proteomic study of microsomal fractions containing the proteins of the secretory pathway. An enrichment analysis of rhythmic proteins highlighted proteins linked to endoplasmic reticulum (ER) and Golgi apparatus (GA) function, mainly including proteins involved in protein folding and glycosylation.