該基因編碼的蛋白質屬于高度保守的細胞周期蛋白家族，其成員在細胞周期內具有顯著的蛋白質豐度周期性。細胞周期蛋白起著調節CDK激酶的作用。不同的細胞周期蛋白表現出不同的表達和降解模式，這有助于每個有絲分裂事件的時間協調。該細胞周期蛋白與CDK4或CDK6形成復合物并作為其調節亞單位發揮作用，其活性是細胞周期G1/S轉換所必需的。這種蛋白與腫瘤抑制蛋白Rb的磷酸化相互作用并參與其中。據報道，與該細胞周期蛋白相關的CDK4活性對紫外線照射后細胞周期通過G2期進入有絲分裂是必要的。一些轉錄變體編碼不同的亞型已被發現的這個基因。
The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with and functions as a regulatory subunit of CDK4 or CDK6, whose activtiy is required for cell cycle G1/S transition. This protein has been shown to interact with and be involved in the phosphorylation of tumor suppressor protein Rb. The CDK4 activity associated with this cyclin was reported to be necessary for cell cycle progression through G2 phase into mitosis after UV radiation. Several transcript variants encoding different isoforms have been found for this gene.
