WP3529 - Zinc homeostasis - Homo sapiens

Zinc is a transition metal and catalytic cofactor involved in many biological processes such as proliferation, development and differentiation, regulation of DNA synthesis, genomic stability, cell activation, RNA transcription, immune function. Zinc homeostasis in cells is ensured by various protein families including zinc transporters, zinc-binding proteins (Metallothioneins, MTs), transcription factors (MTF1-2). ZnT (1-10) transporters are responsible of zinc efflux and are assigned to the SLC30A family while ZIP (1-14) transporters are responsible for the influx of zinc into the cytoplasm and are assigned to the SLC39A family. Zn2+ enters into the cell by the ZIP transporters, and once inside the cell is available to bind metalloproteins (MT) which deliver to ZnT, or the zinc can bind directly to ZnTs and then deliver in the organelles / vesicles or lead outside the cell. Elevated zinc levels have been reported in different tumor tissue, such as breast and lung cancer.锌是一种过渡金属，同时亦是诸多生物学过程中不可或缺的催化辅因子，这些过程包括细胞增殖、发育与分化、DNA合成调控、基因组稳定性维持、细胞活化、RNA转录及免疫功能调控。细胞内的锌稳态由多类蛋白质家族协同保障，涵盖锌转运蛋白、锌结合蛋白（金属硫蛋白，Metallothioneins，MTs）以及转录因子（MTF1-2）。ZnT（1-10）转运蛋白负责介导锌的外排，隶属于SLC30A家族；而ZIP（1-14）转运蛋白负责将锌摄入细胞质，隶属于SLC39A家族。Zn²+经ZIP转运蛋白进入细胞后，既可以与金属硫蛋白（MT）结合后交由ZnT转运，也可直接与ZnT结合，随后被转运至细胞器/囊泡中，或是被排出细胞外。现有研究表明，乳腺癌、肺癌等多种肿瘤组织内的锌水平存在升高现象。