SR protein

SR protein

SR proteins are Serine/Arginine-rich proteins which are involved in regulating and selecting splice sites in eukaryotic mRNA. Alternative splicing requires SR proteins to select which alternative splice sites should be used.

Most evidences indicated that SR proteins are encoded by essential genes. Recently a RNAi study in C. elegans was not able to confirm the essentiality. However when several SR mRNAs were targeted by RNAi simultaneously, lethality was observed.

Location and translocation

SR proteins are localized in speckle domain in the interphase nucleus. Some SR proteins travel between nucleus and cytoplasm. Subcellular localization of SR proteins are affected by phosphorylation. Recent studies (in 2006) suggest fundamental differences in the regulation of the mobility of plant (ATP dependent) and animal (ATP independent) SR splicing factors.

tructure

All SR proteins have one or two "N-terminal RNA binding domain" and "C-terminal protein interaction domain". The latter which is rich in serine and arginine is called SR domain. Serines in SR domain may be extensively phosphorylated. This is a method by which cell can regulate the localization of the proteins. One SR domain can interact with another SR domain. SR domains and RNA recognition motifs (RRM) are modular. SR domain can be seen in proteins other that SR family.

Function

SR proteins have been shown to have roles in alternative and constitutive splicing inadition to roles in translation.

Exon dependent roles (splicing)

*Recruitment of U1 and U2AF
*Splicing regulatory functions

Exon independent roles (splicing)

*SR protein may have a role in recruiting U4U5U6 tri-complex.

References

*Graveley, Brenton. "Sorting out the complexity of SR protein functions". RNA. 2000 Sep;6(9):1197-1211. Entrez Pubmed|10999598

The members of the SR protein family of pre-mRNA splicing factors have distinct functions in promoting alternative splice site usage. Here we show that SR proteins are required for the first step of spliceosome assembly, interaction of the U1 small nuclear ribonucleoprotein complex (U1 snRNP) with the 5' splice site of the pre-mRNA. Further, we find that individual SR proteins have distinct abilities to promote interaction of U1 snRNP with alternative 5' splice junctions. These results suggest that SR proteins direct 5' splice site selection by regulation of U1 snRNP assembly onto the pre-mRNA.


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Protein folding — Protein thermodynamics redirects here. For the thermodynamics of reactions catalyzed by proteins, see Enzyme. Protein before and after folding. Protein folding is the process by which a protein structure assumes its functional shape or… …   Wikipedia

  • Protein-protein interaction — Protein protein interactions refer to the association of protein molecules and the study of these associations from the perspective of biochemistry, signal transduction and networks. The interactions between proteins are important for many… …   Wikipedia

  • Protein purification — is a series of processes intended to isolate a single type of protein from a complex mixture. Protein purification is vital for the characterisation of the function, structure and interactions of the protein of interest. The starting material is… …   Wikipedia

  • Protein (disambiguation) — Protein is a class of biomolecules composed of amino acid chains.Protein may also refer to:Biochemistry* Antifreeze protein, class of polypeptides produced by certain fish, vertebrates, plants, fungi and bacteria * Conjugated protein, protein… …   Wikipedia

  • Protein adulteration in the People's Republic of China — refers to the adulteration and contamination of several food and feed ingredients with inexpensive melamine and other compounds such as cyanuric acid, ammeline and ammelide. These adulterants can be used to inflate the apparent protein content of …   Wikipedia

  • Protein tyrosine phosphatase — Protein tyrosine phosphatases (PTPs) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins. Protein tyrosine (pTyr) phosphorylation is a common post translational modification that can create novel… …   Wikipedia

  • Protein structure prediction — is one of the most important goals pursued by bioinformatics and theoretical chemistry. Its aim is the prediction of the three dimensional structure of proteins from their amino acid sequences, sometimes including additional relevant information… …   Wikipedia

  • Protein sequencing — Proteins are found in every cell and are essential to every biological process, protein structure is very complex: determining a protein s structure involves first protein sequencing determining the amino acid sequences of its constituent… …   Wikipedia

  • Protein S — is a vitamin K dependent plasma glycoprotein synthesized in the liver. In the circulation, Protein S exists in two forms: a free form and a complex form bound to complement protein C4b. FunctionThe best characterized function of Protein S is its… …   Wikipedia

  • Protein-protein interaction prediction — is a field combining bioinformatics and structural biology in an attempt to identify and catalog interactions between pairs or groups of proteins. Understanding protein protein interactions is important in investigating intracellular signaling… …   Wikipedia

  • Protein subcellular localization prediction — involves the computational prediction of where a protein resides in a cell. Prediction of protein subcellular localization is an important component of bioinformatics based prediction of protein function and genome annotation, and it can aid the… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”