Nucleoporin 210kDa
Encyclopedia
Nuclear pore glycoprotein-210 (gp210) is an essential trafficking regulator in the eukaryotic nuclear pore complex. Gp-210 anchors the pore complex to the nuclear membrane. and protein tagging reveals its primarily located on the luminal side of double layer membrane at the pore.
A single polypeptide motif of gp210 is responsible for sorting to nuclear membrane, and indicate the carboxyl tail of the protein is oriented toward the cytoplasmic side of the membrane.

Disassembly and Assembly

During eukaryotic mitosis
Mitosis
Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...

 the nuclear envelope
Nuclear envelope
A nuclear envelope is a double lipid bilayer that encloses the genetic material in eukaryotic cells. The nuclear envelope also serves as the physical barrier, separating the contents of the nucleus from the cytosol...

 disentegrates into vesicles
Vesicle (biology)
A vesicle is a bubble of liquid within another liquid, a supramolecular assembly made up of many different molecules. More technically, a vesicle is a small membrane-enclosed sack that can store or transport substances. Vesicles can form naturally because of the properties of lipid membranes , or...

 dispersing nuclear lamina proteins and nuclear pore complexes. Nup210 is specifically phosphorylated on the C-terminal (cytoplasmic) domain in mitosis at Ser1880 and is dispersed throughout the endoplasmic reticulum
Endoplasmic reticulum
The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae...

 during mitosis as homodimers. Nuclear lamins begin to reassemble around chromosomes at the end of mitosis. Nup210 lags the reassembly process relative to other Nups. and while much of the assembly process can occur without it, the final assembly and dilation of the complexes require nup210. The replacement of serine
Serine
Serine is an amino acid with the formula HO2CCHCH2OH. It is one of the proteinogenic amino acids. By virtue of the hydroxyl group, serine is classified as a polar amino acid.-Occurrence and biosynthesis:...

 at position 1880 with a phosphorylated 'looking' glutamate results in Nup120 complexes that fail to reassemble indicating that dephosphorylation
Dephosphorylation
Dephosphorylation is the essential process of removing phosphate groups from an organic compound by hydrolysis. Its opposite is phosphorylation...

 of Nup120 within the final phases of proper assembly is required.

Pathology

Recognized by anti-nuclear antibodies found in primary biliary cirrhosis
Primary biliary cirrhosis
Primary biliary cirrhosis, often abbreviated PBC, is an autoimmune disease of the liver marked by the slow progressive destruction of the small bile ducts within the liver. When these ducts are damaged, bile builds up in the liver and over time damages the tissue. This can lead to scarring,...

 (PBC) anti-Nup210 antibodies
Anti-glycoprotein-210 antibodies
Anti-glycoprotein-210 antibodies are directed at gp210 and are found within primary biliary cirrhosis patients in high frequency. AGPA recognize the cytoplasmic oriented carboxyl terminus of the protein...

 correlate with progression toward end stage liver disease. Nup210 is possibly a destructive autoimmune target of the disease. One idea for the loss of tolerance is the increased or abnormal expression of Nup120 in patients with PBC.

anti-mitochondral
Anti-mitochondrial antibodies
Anti-mitochondrial antibodies are autoantibodies, consisting of immunoglobulins formed against mitochondria, primarily mitochondria in cells of the liver...

, anti-centromere
Anti-centromere antibodies
Anti-centromere antibodies occur in auto immune disorders; frequently in limited systemic scleroderma, , and, occasionally are found in the diffuse form of scleroderma...

  and anti-nup62
Anti-p62 antibodies
Anti-p62 antibodies are found in a primary biliary cirrhosis. p62 is also more frequent in Stage IV primary biliary cirrhosis and is prognostic for severe disease. The autoantigen is the nucleoporin 62kDA protein....

 are also found in PBC
Primary biliary cirrhosis
Primary biliary cirrhosis, often abbreviated PBC, is an autoimmune disease of the liver marked by the slow progressive destruction of the small bile ducts within the liver. When these ducts are damaged, bile builds up in the liver and over time damages the tissue. This can lead to scarring,...

.
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