Pdp1, short for pyruvate dehydrogenase phosphatase catalytic subunit 1, is a key enzyme in the metal-dependent Ser/Thr protein phosphatase PPM family [6]. It dephosphorylates and activates pyruvate dehydrogenase (PDH), stimulating the conversion of pyruvate into acetyl-CoA, thus playing a vital role in cellular energy metabolism [3]. It is also involved in multiple signaling pathways, such as the RAS signaling axis, MAPK signaling, and JAK/STAT3 signaling pathway, and is of great biological importance in various physiological and pathological processes [1,2,4].

In FLT3-ITD-positive acute myeloid leukemia (AML), Pdp1 knockdown reduces cellular respiration and impairs the proliferation of FLT3-ITD cells, and Pdp1 modifies the response to FLT3 inhibition, enhancing or diminishing drug resistance [1]. In KRAS mutant colorectal cancer, Pdp1 acts as a scaffold to enhance BRAF and MEK1 interaction, accelerating cancer progression, and targeting Pdp1 combined with MAPK inhibitors can inhibit the cancer [2]. In breast cancer, Pdp1 knockdown suppresses cell amplification, migration, and triggers apoptosis through the STAT3 pathway [4]. In ovarian cancer, Pdp1 promotes cell proliferation, invasion, and migration, and is associated with patient prognosis and chemosensitivity [5]. In Drosophila, Pdp1 is part of a secondary feedback loop in the circadian clock, and its interaction with TARANIS and VRILLE modulates the circadian transcriptional feedback mechanism [7,8]. In crickets, Pdp1 plays important roles in the circadian clock [9].

In conclusion, Pdp1 is a crucial regulator in multiple biological processes. Its functions in energy metabolism and various signaling pathways contribute to the development and progression of many diseases, including AML, colorectal cancer, breast cancer, and ovarian cancer. The study of Pdp1 using gene-knockout or other loss-of-function models has provided valuable insights into its role in these disease conditions, facilitating a better understanding of the underlying mechanisms and potentially leading to new therapeutic strategies.