AK6 (adenylate kinase 6) is a nuclear-localized phosphotransferase with broad substrate specificity that catalyzes reversible phosphoryl transfer between nucleoside triphosphates and monophosphates 1. The enzyme preferentially phosphorylates AMP and dAMP using CTP as the optimal phosphate donor 1. Beyond nucleotide metabolism, AK6 plays critical roles in 40S ribosomal subunit maturation through its ATPase activity, facilitating conformational changes in 18S rRNA by transiently removing ribosomal protein uS11 2. AK6 also regulates ion homeostasis by modulating WNK1 phosphorylation states, affecting chloride channel activity and cell proliferation 3. The protein is implicated in multiple disease contexts: reduced AK6 expression correlates with asthenospermia and impaired sperm motility 4, while glial AK6 dysfunction represents a potential therapeutic target in Parkinson's disease through adenosine metabolism regulation 5. AK6 dysfunction is associated with cancer development and progression, involving effects on gene transcription, cell metabolism, DNA damage responses, and genome stability 6. Additionally, AK6 may regulate Cajal body formation 1. Its nuclear localization distinguishes AK6 from other adenylate kinase isoforms, positioning it as a critical regulator of nuclear energy homeostasis and nucleotide-dependent processes.