This study investigated the regulatory roles of the mokC, mokD, and LaeA genes in Monacolin K production by Monascus purpureus. Overexpression strains C8 (mokC), D8 (mokD), and L3 (LaeA) were compared with the wild-type M1 strain. Relative and absolute quantitative proteomic analyses identified Monacolin K-related regulatory protein changes in wild-type and overexpression strains. Although growth indices between strains were not significantly different, metabolic indices differed significantly. Overexpression strains affected transcriptional and translational regulation, the tricarboxylic acid cycle, and polyketide bioreaction processes. mokC overexpression affected lysine and glutamate content, enhanced carbohydrate metabolism, and influenced polyketide reactions, increasing Monacolin K secretion. mokD overexpression affected the tricarboxylic acid cycle, directing more acetyl coenzyme A into Monacolin K synthesis and increasing its production. LaeA enhanced translation and enzyme activity, regulating secondary metabolic pathways and increasing Monacolin K production. This study provides insights into the metabolic- and protein-level regulation of Monacolin K synthesis.