XPC基因（全称xeroderma pigmentosum complementation group C）属于核苷酸切除修复（NER）通路中的关键基因家族，负责修复DNA损伤，尤其是紫外线（UV）或化学物质引起的嘧啶二聚体等大片段损伤。其编码的XPC蛋白作为损伤识别复合物的核心组分，与HR23B等蛋白结合形成XPC复合物，在全局基因组修复（GG-NER）中率先扫描DNA并识别扭曲的螺旋结构，启动修复过程。XPC蛋白本身不具备酶活性，但能招募TFIIH等下游修复因子。该基因突变会导致着色性干皮病（XP），患者表现为紫外线极度敏感、皮肤癌高风险及神经系统异常，因为突变使XPC蛋白功能丧失，导致损伤DNA积累。XPC基因过表达可能增强DNA修复能力，但异常高表达或干扰其他修复通路平衡；而表达降低则直接削弱NER效率，增加基因组不稳定性。XPC属于XP基因家族（含XPA-XPG等7个互补群），这些基因均参与NER但功能阶段不同：XPA验证损伤，XPB/XPD解旋DNA，XPF/ERCC1和XPG负责切割损伤链等。家族共性为协同完成损伤识别、解旋、切除及修复合成。研究还发现XPC在氧化损伤修复和某些化疗耐药性中起作用，其表达水平可能影响癌症治疗效果。

该基因编码的核苷酸切除修复（NER）途径的组分。有参与NER途径多个组件，包括着色性干皮（XP）AG和V，科凯恩综合征（CS）的A和B，以及trichothiodystrophy（TTD）A组，等等。这种成分，XPC，起着在重要的作用全球基因组NER的早期步骤，尤其是在损害识别，开放的复杂的形成和修复的蛋白复合物的形成。该基因或其他一些NER成分突变导致着色性干皮，一种罕见的常染色体隐性遗传疾病在早期的年龄特点与癌的发展日光敏感性增加。另外剪接转录变体也发现了这种基因。 [由RefSeq的，2009年03月提供]

The XPC gene, standing for xeroderma pigmentosum complementation group C, encodes a critical protein within the nucleotide excision repair (NER) pathway that specializes in the recognition and repair of bulky DNA lesions, particularly pyrimidine dimers induced by ultraviolet (UV) radiation or chemical carcinogens. As a central component of the damage recognition complex, the XPC protein associates with HR23B to form the XPC-HR23B complex, which actively scans the genome to detect helical distortions characteristic of global genome NER (GG-NER). Although the XPC protein lacks intrinsic enzymatic activity, it serves as a vital scaffold that recruits downstream repair factors, such as the TFIIH helicase complex, to initiate the unwinding of the damaged DNA strand. Mutations in XPC result in the autosomal recessive disorder xeroderma pigmentosum (XP), characterized by extreme photosensitivity, a markedly elevated risk of cutaneous malignancies, and potential neurological abnormalities due to the accumulation of unrepaired DNA damage. XPC is one of seven complementary groups (XPA through XPG) within the XP gene family, each contributing to distinct stages of the NER cascade; while XPA verifies damage and XPB/XPD unwind the DNA, XPF/ERCC1 and XPG execute the incision of the damaged strand, collectively ensuring the coordinated removal and resynthesis of the excised segment. Beyond UV-induced damage, XPC also plays a role in repairing oxidative DNA lesions and may influence resistance to chemotherapy, suggesting that its expression levels can modulate genomic stability and impact the efficacy of cancer treatments.

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