Coilin is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''COIL''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. Coilin got its name from the coiled shape of the Cajal bodies in which it is found. It was first identified using human autoimmune serum.

Function

Coilin protein is one of the main molecular components of Cajal bodies. Cajal bodies are non-membrane bound

nuclear bodies Nuclear bodies (also known as nuclear domains or nuclear dots) are biomolecular condensates, membraneless structures found in the Cell nucleus, cell nuclei of eukaryote, eukaryotic cell (biology), cells. Nuclear bodies include Cajal body, Cajal b ...

of varying number and composition that are involved in the

post-transcriptional modification Transcriptional modification or co-transcriptional modification is a set of biological processes common to most eukaryotic cells by which an RNA primary transcript is chemically altered following transcription from a gene to produce a mature, f ...

of small nuclear and small nucleolar RNAs. In addition to its structural role, coilin acts as glue to connect the CB to the

nucleolus The nucleolus (; : nucleoli ) is the largest structure in the cell nucleus, nucleus of eukaryote, eukaryotic cell (biology), cells. It is best known as the site of ribosome biogenesis. The nucleolus also participates in the formation of signa ...

. The

N-terminus The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the amin ...

of the coilin protein directs its self-oligomerization while the

C-terminus The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, carboxy tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein Proteins are large biomolecules and macromolecules that comp ...

influences the number of nuclear bodies assembled per cell. Differential

methylation Methylation, in the chemistry, chemical sciences, is the addition of a methyl group on a substrate (chemistry), substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replac ...

and

phosphorylation In biochemistry, phosphorylation is described as the "transfer of a phosphate group" from a donor to an acceptor. A common phosphorylating agent (phosphate donor) is ATP and a common family of acceptor are alcohols: : This equation can be writ ...

of coilin likely influences its localization among nuclear bodies and the composition and assembly of Cajal bodies. This gene has

pseudogene Pseudogenes are nonfunctional segments of DNA that resemble functional genes. Pseudogenes can be formed from both protein-coding genes and non-coding genes. In the case of protein-coding genes, most pseudogenes arise as superfluous copies of fun ...

s on chromosome 4 and chromosome 14. To study CBs, coilin can be combined with GFP (

Green Fluorescent Protein The green fluorescent protein (GFP) is a protein that exhibits green fluorescence when exposed to light in the blue to ultraviolet range. The label ''GFP'' traditionally refers to the protein first isolated from the jellyfish ''Aequorea victo ...

) to form Coilin-GFP hybrid protein. The hybrid protein can then be used to locate CBs underneath a microscope, usually near the nucleolus of the cell. Other proteins that make up the CB include snRNPs and nucleolar snoRNPs. Coilin has been shown to interact with ataxin 1, nucleolar phosphoprotein p130, SMN, and SNRPB.

Function

References

Further reading