Sjögren syndrome type B antigen (SS-B) also known as Lupus La protein is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the SSB gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

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Function

La is involved in diverse aspects of RNA metabolism, including binding and protecting 3-prime UUU (OH) elements of newly RNA polymerase III

RNA polymerase III

RNA polymerase III transcribes DNA to synthesize ribosomal 5S rRNA, tRNA and other small RNAs. The genes transcribed by RNA Pol III fall in the category of "housekeeping" genes whose expression is required in all cell types and most environmental conditions...

-transcribed RNA, processing 5-prime and 3-prime ends of pre-tRNA precursors, acting as an RNA chaperone, and binding viral RNAs associated with hepatitis C

Hepatitis C

Hepatitis C is an infectious disease primarily affecting the liver, caused by the hepatitis C virus . The infection is often asymptomatic, but chronic infection can lead to scarring of the liver and ultimately to cirrhosis, which is generally apparent after many years...

 virus. La protein was originally defined by its reactivity with autoantibodies from patients with Sjögren's syndrome

Sjögren's syndrome

Sjögren's syndrome , also known as "Mikulicz disease" and "Sicca syndrome", is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands that produce tears and saliva....

 and systemic lupus erythematosus

Systemic lupus erythematosus

Systemic lupus erythematosus , often abbreviated to SLE or lupus, is a systemic autoimmune disease that can affect any part of the body. As occurs in other autoimmune diseases, the immune system attacks the body's cells and tissue, resulting in inflammation and tissue damage...

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Interactions

Sjögren syndrome antigen B has been shown to interact

Protein-protein interaction

Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...

 with nucleolin

Nucleolin

Nucleolin is a protein that in humans is encoded by the NCL gene.- Gene :The human NCL gene is located on chromosome 2 and consists of 14 exons with 13 introns and spans approximately 11kb...

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