Background: About one-third of the CYP enzymes identified so far, including several novel CYP enzymes such as CYP2S1, CYP2U1 and CYP2W1, belong to the CYP2 family. As with other recently discovered CYP enzymes, detailed information about the catalytic activity and function of CYP2S1 is lacking.
Objective: To review and compare the expression of CYP2S1 mRNA and protein in humans, mice and rats, and to critically examine evidence pertaining to CYP2S1 regulation and its catalytic activity.
Methods: Information about mouse and human CYP2S1 was summarized from published reports. Data about rat CYP2S1 expression was taken from recent work by the authors.
Results/conclusions: CYP2S1 shares molecular characteristics of both CYP1 and CYP2 family enzymes but shows a unique tissue profile of expression. Further studies are needed to identify selective substrates and to measure CYP2S1 protein levels before the role of CYP2S1 in xenobiotic metabolism and its relevance to physiological pathways and disease states can be determined.