中文摘要：

C1q蛋白家族由众多含C1q结构域的蛋白组成,从细菌到高等哺乳动物中都有分布。这类蛋白由一条信号肽、胶原样区（Collage-like region,CLR）和C1q球状结构域（Globular C1q domain,gC1q）组成。C1q蛋白家族根据其结构特点,可分为三大类分子：C1q、C1q-like和ghC1q。C1q是补体经典途径的起始分子,能够识别免疫复合物,启动补体系统经典途径;此外,作为一种模式识别受体分子（Pattern recognition receptor,PRR）,它可以结合种类繁多的配体。C1q-like蛋白的结构类似于C1q分子,含有CLR和gC1q结构域,在水蛭中参与神经系统的修复,在脊椎动物中实现从凝集素到免疫球蛋白结合分子的功能转变,参与补体系统的激活。ghC1q蛋白只具有gC1q结构域和一段短的N末端序列,包括分泌型蛋白（sghC1q）和非分泌型蛋白（cghC1q）。sghC1q在无脊椎动物固有免疫系统中发挥重要作用;脊椎动物中的sghC1q可作为一类新型跨神经元调节因子,在大脑的许多区域调节突触发育和突触可塑性。cghC1q基因最早可追溯至芽孢杆菌属的细菌中,具有典型的gC1q果冻卷结构,说明gC1q结构域有着非常悠久的进化历程且结构高度保守。文章对C1q蛋白家族的结构、分布、分类以及功能进行综述,以期为从事该领域研究的科研人员提供有益参考。

英文摘要：

The C 1 q protein family consists of many proteins containing a C 1 q domain, which exists widely within organisms from bacteria to mammals. The domain organization of these proteins mainly includes a leading signal peptide, a collagen-like region, and a globular C1q domain. According to their structural characteristics, the C1q protein family can be divided into three subgroups： C1q, C1q-like and ghC1q. C1q, as the first subcomponent of classical pathway in the com- plement system, has the ability to bind immune complexes and triggers activation of the classical complement pathway. Inaddition, it can be a pattern recognition receptor with the unique ability to sense an amazing variety of ligands. C1q-like protein contains a collagen-like region and a globular C1q domain which is similar to C1q molecule. It involves in leech central nervous system repair. However, in vertebrates, its function converts from a lectin to an immunoglobulin binding molecule and it involves in the activation of complement system. The structure of ghC1q protein is composed of a globular C1q domain and a short N-terminal sequence. This protein contains secreted globular head C1q proteins and cellular globular head C1q proteins. The sghC1q protein plays an important role in the innate immune system of invertebrates. The sghC 1 q proteins that belong to vertebrates may serve as a new class of transneuronal regulators of synapse development and synaptic plasticity in various brain regions. The earliest cghC1q gene can be traced back to bacteria of the genus Bacillus. Its stereotypical gC1q jelly roll topology substantiates that the gC1q domain has an ancient evolutionary history and a highly conserved structure. This review focuses on the structure, distribution, classification, and function of C1q family proteins, providing valuable clues for the future research in this field.