PCK2
Description
The PCK2 (phosphoenolpyruvate carboxykinase 2, mitochondrial) is a protein-coding gene located on chromosome 14.
Phosphoenolpyruvate carboxykinase 2, mitochondrial (PCK2, PEPCK-M), is an isozyme of phosphoenolpyruvate carboxykinase (PCK, PEPCK) that in humans is encoded by the PCK2 gene on chromosome 14. This gene encodes a mitochondrial enzyme that catalyzes the conversion of oxaloacetate (OAA) to phosphoenolpyruvate (PEP) in the presence of guanosine triphosphate (GTP). A cytosolic form of this protein is encoded by a different gene and is the key enzyme of gluconeogenesis in the liver. Alternatively spliced transcript variants have been described. The PCK2 gene encodes the mitochondrial form of PCK and shares a 68% homology in DNA sequence with PCK1 and 70% homology in amino acid sequence with its encoded cytosolic form, PCK1. Moreover, PCK2 shares structural homology with PCK1, indicating that the genes originated from a common ancestor gene. Nonetheless, though both genes possess ten exons and nine introns, the sizes of their introns may differ by ~2 kb, with the largest intron in PCK2 spanning 2.5 kb. Altogether, the total length of the PCK2 gene spans ~10 kb. Another difference is the presence of Alu sequences in its introns that are absent in PCK1. PCK2 also contains an 18-residue mitochondrial targeting sequence at its N-terminal. Potential regulatory elements, including five GC boxes and three CCAAT boxes, lie 1819 bp upstream of the transcription start site.
PCK2 is also known as PEPCK, PEPCK-M, PEPCK2, mtPCK2.
