Cif type III effector protein: a smart hijacker of the host cell cycle
Résumé
During coevolution with their hosts, bacteria have developed functions that allow them to interfere with the mechanisms controlling the proliferation of eukaryotic cells. Cycle inhibiting factor (Cif) is one of these cyclomodulins, the family of bacterial effectors that interfere with the host cell cycle. Acquired early during evolution by bacteria isolated from vertebrates and invertebrates, Cif is an effector protein of type III secretion machineries. Cif blocks the host cell cycle in G1 and G2 by inducing the accumulation of the cyclin-dependent kinase inhibitors p21waf1/cip1 and p27kip1. The x-ray crystal structure of Cif reveals it to be a divergent member of a superfamily of enzymes including cysteine proteases and acetyltransferases. This review summarizes and discusses what we know about Cif, from the bacterial gene to the host target.