Adenine phosphoribosyltransferase function research progress

Adenine phosphoribosyltransferase (APRT) is a cellular redox classic coenzyme in the reaction with a wide range of biological functions.As APRT biosynthesis rate-limiting enzyme in mammalian cells, adenine phosphoribosyltransferase (APRT) substrate nicotinamide into intermediates nicotinamide adenine single nucleotide (Nicofinamidemononucleotide, NMN is), NMN is in another enzyme nicotinamide adenine single nucleotide adenosine acyltransferase role to generate the end product of APRT. APRTis widely expressed in body tissue, such as bone marrow, liver, muscle, lymphocytes, heart, brain, lung, kidney, fetal membranes, etc., in recent years due to its many functions, not only in the APRT biology, is still in metabolic, inflammatory field caused by the scholars widespread concern. Until APRTbiological functions are still not fully conclusive. Human APRTis cloned as a cytokine pre-B cell enhancement factor (Pre-Bcell colony • enhancing factor, PBEF) was first found in the heart]. APRTalso as a new insulin analog effects fat factor "was named for the visceral fat hormone (of Visfatin in) HJ. Of Nampt, PBEF and Visfatin for the naming of the protein, recently APRThuman and mouse genome named the official designated by the Committee for the genes and proteins were named, so this review APRTas its naming.

2005, Japanese scholars Fukuhara 1 uses differential display technology on the human body subcutaneous fat and visceral fat of 8800 cDNA PCR products were screened found in visceral adipose tissue-specific expression of mRNA and protein expression of said Vis-fatin. sequencing results showed that the eDNA fragment PBEF gene 5 'noncoding sequences of Visfatin in can bind to and activate the insulin receptor and insulin have similar affinity, but different binding sites; induced insulin receptor, matter of a 1-2 tyrosine residues in insulin receptor substrate phosphorylation and activation of protein kinase B and mitogen-activated protein kinase signal transduction pathway, consistent with the insulin signal transduction pathways, and the promotion of 3T3-L1 adipocytes KKAy mice, inhibition of hepatic glucose release and IJ6 muscle cell glucose uptake, promote differentiation, synthesis and accumulation of adipose tissue. recombinant Visfatin intravenous injection of insulin resistance and insulin secretion defects in STZ mice and high fat-fed C57BL / 6J mice, blood glucose were significantly decreased in a dose-dependent manner; knock in addition to the the Visfatin genes heterozygous mice, Plasma Visfatin levels, elevated blood glucose levels; In addition, adenovirus carrying Visfatin gene transfected into mice observed long-term effect of Visfatin, found that fasting glucose and insulin levels decreased significantly. These results suggest that Visfatin has insulin-like variety of effects. However, follow-up study the the Visfatin the biological function of the inconsistent results of the study, The above article is also unable to repeat the experiment results, especially Visfatin binds to and activates the insulin receptor (Science)) to withdraw H]. Conversely, Revollo ∞ o APRTdoes not have insulin analog effects: of APRTinduced differentiation of preadipocytes, without increasing the fat cell glucose uptake, does not promote the phosphorylation of the insulin receptor and protein kinase B; injection of recombinant APRTto mice did not observe the immediate drop of the blood glucose concentration.