Investigation of the effects and underlying mechanisms of adenylate kinase 1 on inosine monophosphate deposition in Beijing-You chickens

Inosine monophosphate (IMP) is a major flavor compound in meat. Given the observed positive correlation between adenylate kinase 1 (AK1) expression and IMP content in Beijing-You chickens (BJYs), we investigated the role of AK1 in regulating myoblast proliferation and differentiation. Cell counting kit-8 (CCK-8) assays, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, flow cytometry, and Western blotting showed that AK1 promoted myogenic differentiation and suppressed the proliferative activity of myoblasts. During the proliferation of myoblasts, glutamine phosphoribosylpyrophosphate amidotransferase (GPAT) was suppressed by AK1 and adenylosuccinate synthase (ADSS) was enhanced, which led to reduced IMP accumulation and inhibited uric acid (UA) and adenosine triphosphate (ATP) production. During myoblast differentiation, the protein expression of de novo IMP synthesis genes, including GPAT, 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (PurH), and adenylosuccinate lyase (ADSL), was upregulated, while ADSS was downregulated by AK1, resulting in enhanced IMP deposition and stimulated production of UA and ATP. In summary, this study elucidates the regulatory role of AK1 in coordinating the proliferation and differentiation of myoblasts, as well as its stage-specific modulation of IMP anabolism. These findings provide theoretical insights into the molecular mechanisms governing IMP deposition and offer potential guidance for improving meat flavor quality in chicken through molecular breeding strategies.