Cdkn1A-interacting zinc finger protein 1 (CIZ1) was first identified in a yeast-2-hybrid system searching for interacting proteins of CDK2 inhibitor p21(Cip1/Waf1). Ciz1 also binds to CDK2, cyclin A, cyclin E, CDC6, PCNA, TCF4 and estrogen receptor-α. Recent studies reveal numerous biological functions of CIZ1 in DNA replication, cell proliferation, and differentiation. In addition, splicing variants of CIZ1 mRNA is associated with a variety of cancers and Alzheimer's disease, and mutations of the CIZ1 gene lead to cervical dystonia. CIZ1 expression is increased in cancers and rheumatoid arthritis. In this review, we will summarize the biological functions and molecular mechanisms of CIZ1 in these physiological and pathological processes.
Keywords: CIZ1; DNA replication; alternative splicing; cell cycle.