{'fraction_non_alphanumeric': 0.021335168616655197, 'fraction_numerical': 0.026841018582243633, 'mean_word_length': 5.956937799043062, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Detection of a Novel Quiescence-dependent Protein Kinase*

We have identified a cell quiescence-specific 33-kDa cytoplasmic protein kinase (p33QIK,Quiescence-Induced Kinase) based on induction of p33QIK-specific kinase activity of cells growth-arrested in the quiescent phase and deactivation upon entry into the cell cycle. Blockage of macromolecular synthesis prevents p33QIK from deactivation, indicating a requirement of newly synthesized regulators for deactivation of p33QIK during G0/G1 transition. Stress shock induces additional increases of p33QIK activity in a quiescence-dependent manner that correlates with induction of apoptosis. Using a specific antibody to Krs1/Mst2 protein, we found that p33QIK is related to p63Krs1 and is distinguishable from a 36-kDa protein kinase, which is induced through proteolytic modification of activated p63Krs1 in proliferating cells undergoing apoptosis. p33QIK is constantly expressed in quiescent, proliferating, and apoptotic quiescent cells. Regulation of p33QIK activity involves protein phosphorylation/dephosphorylation in a proteolysis-independent manner. Regulation of p33QIK and related p63Krs1 and p36 appears to involve distinct pathways in quiescent and proliferating cells, respectively. Our results illustrate the relevance of p33QIK activity for cell quiescence that may provide a new insight into signaling pathways regulated in cells during quiescence and quiescence-related apoptosis.