Cre Recombinase: a genomic manipulation tool

Abstract

Comprehending human biology necessitates an understanding of molecular mechanisms that contribute to human physiology. For example, to determine why drug users relapse after stress, researchers must identify the neurological pathways involved in the addiction, and understand how certain stimuli trigger relapse. When using Cre recombinase and the LoxP DNA sites (from P1 bacteriophages), no limitations exist for knocking genes in or out and any genetic disease can be researched. By using the Cre‐LoxP system, researchers can manipulate gene expression in specific tissues by excising, inverting, inserting, and translocating sections of DNA. Cre, a 38kD protein with 341 amino acids, has 14 alpha helices and five strands of beta sheets. Cre has two domains, the N‐terminus (amino acids 20–129) and the C‐terminus (amino acids 132–341). The active site of Cre contains the residues of Arg173, His289, Arg292, Trp315, and Tyr324 which catalyzes the interactions with LoxP. This interaction facilitates the genome change and affects whether or not certain genes are expressed. The Brown Deer High School SMART (Students Modeling A Research Topic) Team has designed a model of Cre Recombinase using 3D printing technology to investigate structure‐function relationships. The Cre‐LoxP system has become a routine lab practice. For example, in animal models the interface of stress triggers and relapse is being researched using CRE‐delivery approaches to express genes in pathways that may be critical to stress and relapse. Using the Cre‐LoxP system in drug addiction studies is only one example of the system’s utility in understanding human physiology and disease mechanisms.