Pck1 Conditional Knockout mouse models

Pck1 encodes cytosolic phosphoenolpyruvate carboxykinase, the mouse ortholog of human PCK1, which commits mitochondrially derived oxaloacetate to phosphoenolpyruvate in a GTP-dependent decarboxylation that sets the flux ceiling for hepatic and renal gluconeogenesis and for adipose glyceroneogenesis. Transcription rather than allostery dominates its control: glucagon acting through cAMP and CREB, the glucocorticoid receptor, FOXO1 and PGC-1 alpha drive the promoter, while insulin signaling through AKT suppresses it, making the locus a canonical readout of fasting and insulin resistance. Whole-body deletion is neonatally lethal with massive hepatic steatosis, so albumin-Cre or adipocyte-restricted conditional nulls are required to separate liver from adipose contributions, and promoter-replacement or inducible overexpression alleles test whether transcriptional derepression alone raises glucose output. The mitochondrial paralog Pck2 supplies partial cataplerotic flux but does not rescue cytosolic gluconeogenesis, so compound designs are advisable when quantifying whole-body glucose production.

A floxed Pck1 allele paired with Cre gives spatial control that whole body knockouts cannot offer. People use it to separate developmental roles from adult homeostasis, to model somatic mutations, and to match disease that begins in one organ.