Nup62

Diseases:
Primary Biliary Cirrhosis

Primary biliary cirrhosis (PBC) is an autoimmune chronic cholestatic liver disease characterized by destruction of intrahepatic bile ducts and development of cirrhosis and liver failure. Serologically, PBC is characterized by the presence of antimitochondrial (AMA, M2) antibodies. The immunological profile of PBC also includes antinuclear antibodies (ANA), presenting two distinct patterns, multiple nuclear dots (MND) and rim-like/membranous patterns in IIF. Sp100 and promyelocytic leukemia antigen account for the MND pattern, and gp210, nucleoporin p62 and lamin B receptor are associated with nuclear membrane staining.

Nucleoporins are essential components of the nuclear pore complex, a structure extending across the nuclear envelope, forming a gateway that controls the flow of macromolecules between nucleus and cytoplasm.

Nup62 is a 55 kDa protein and is localized to the nuclear pore central plug, regulating the import of proteins containing nuclear localization signals. The N-terminal domain of this protein plays a role in the nucleocytoplasmic transport, whereas the C-terminus is likely to function in anchorage of p62 to the pore complex.

There is now evidence that anti-Nup62 antibodies occur even more frequently in PBC sera than the autoantibodies against gp210 glycoprotein. Interestingly, several patient sera negative for M2 antibodies, but with a positive IIF pattern for nuclear membrane could be shown to be anti-Nup62 positive.

Nup62 antigen from DIARECT is produced in the baculovirus / insect cell expression system.

相关疾病：原发性胆汁性肝硬化原发性胆汁肝硬化（PBS）是一种慢性的炎症性自身免疫肝病，病理表现包括肝内胆管的阻塞，干扰胆汁的分泌，导致肝硬化和肝衰竭。临床特征包括疲劳、搔痒和黄疸。PBC的特征为存在抗线粒体抗体（AMA，M2）。在90-95% 的PBC病人血清中通过IIF可检测到抗线粒体的抗体（M2），它们和其他的一些核内以及核膜的抗原（Sp100，gp210）的抗体，都是重要的标记物，分为多核点型（MND）抗核抗体和核膜型（NM）。SP100和前髓细胞性白血病抗原属于MND型，而gp210，核孔蛋白p62和核纤层蛋白B受体属于核膜型除了特异性自身抗体。核孔蛋白是核孔复合体的重要组成部分，具有跨越核被膜的延伸结构，形成了一个可以控制细胞核和细胞质之间的大分子流动孔的网关。 
    Nup62是一种55kDa的膜蛋白，定位于核孔中心，调控包含核定位信号等蛋白的输入。该蛋白的N末端区域在核与质的运输过程中起重要作用，C末端区域的功能可能是让p62锚定到孔复合体上。有新的证据表明，抗Nup62抗体在原发性胆汁肝硬化患者血清中检出的频率比抗gp210抗体的要高。有趣的是，很多患者的血清中检出抗M2抗体阴性，但用IIF检测核膜发现Nup62抗体阳性。DIARECT生产的Nup62抗原在杆状病毒/昆虫细胞表达系统中表达的。