Cytoplasmic FMR1-interacting protein 2 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

that in humans is encoded by the ''CYFIP2''

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

. Cytoplasmic FMR1 interacting protein is a 1253 amino acid long protein and is highly conserved sharing 99% sequence identity to the mouse protein. It is expressed mainly in brain tissues, white blood cells and the kidney.

Interactions

CYFIP2 has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizat ...

with

FMR1 ''FMR1'' (Fragile X Messenger Ribonucleoprotein 1) is a human gene that codes for a protein called ''fragile X messenger ribonucleoprotein'', or FMRP. This protein, most commonly found in the brain, is essential for normal cognitive development ...

. CYFIP2 is a p-53 inducible protein and also interacts with the Fragile=X mental retardation protein.Schenck, A., Bardoni, B., Moro, A., Bagni, C., Mandel, J.-L. (2001) Proceedings of the National Academy of Sciences of the United States of America, 98, 8844-8849.

RNA editing

The pre-

mRNA In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein. mRNA is created during the ...

of this protein is subject to

RNA editing RNA editing (also RNA modification) is a molecular process through which some cells can make discrete changes to specific nucleotide sequences within an RNA molecule after it has been generated by RNA polymerase. It occurs in all living organisms ...

. The editing site was previously recorded as a single nucleotide polymorphism (rs3207362) in the dbSNP.

Type

A to I RNA editing is catalyzed by a family of

adenosine deaminase Adenosine deaminase (also known as adenosine aminohydrolase, or ADA) is an enzyme () involved in purine metabolism. It is needed for the breakdown of adenosine from food and for the turnover of nucleic acids in tissues. Its primary function i ...

s acting on RNA (ADARs) that specifically recognize adenosines within double-stranded regions of pre-mRNAs and deaminate them to

inosine Inosine is a nucleoside that is formed when hypoxanthine is attached to a ribose ring (also known as a ribofuranose) via a β-N9-glycosidic bond. It was discovered in 1965 in analysis of RNA transferase. Inosine is commonly found in tRNAs and is ...

. Inosines are recognised as guanosine by the cells translational machinery. There are three members of the ADAR family ADARs 1-3 with

ADAR1 Adar ( he, אֲדָר ; from Akkadian ''adaru'') is the sixth month of the civil year and the twelfth month of the religious year on the Hebrew calendar, roughly corresponding to the month of March in the Gregorian calendar. It is a month of 2 ...

and ADAR2 being the only enzymatically active members. ADAR3 is thought to have a regulatory role in the brain. ADAR1 and ADAR 2 are widely expressed in tissues while ADAR3 is restricted to the brain. The double stranded regions of RNA are formed by base-pairing between residues in the close to region of the editing site with residues usually in a neighboring intron but can be an exonic sequence. The region that base pairs with the editing region is known as an Editing Complementary Sequence (ECS).

Site

An editing site was found in the pre-mRNA of this protein. The substitution occurs within amino acid position 320 in humans and also in mice. A possible double stranded RNA region has not been detected for this pre-mRNA. No double stranded region required by ADARs has predicted. Immunoprecipitation experiments and RNA interference have shown that ADAR 2 is likely to be the main editing enzyme for this site with ADAR 1 having a minor role.

Regulation

Editing seems to be differentially regulated in different tissues. The highest level of editing occurs in the cerebellum with lower frequency of editing detected in human lung, prostrate and uterus tissues. Editing frequency varies from 30-85% depending on tissue.{ There is some evidence for a decrease in CYFIP2 editing with increased age.

Conservation

Editing of the pre-mRNA of this gene has been detected in mouse and chicken.

Effects of RNA editing

Structural

Editing results in a codon change resulting in a

glutamic acid Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...

being translated instead of a

lysine Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated form under biological conditions), an α-carboxylic acid group (which is in the deprotonated &minu ...

Functional

Currently unknown but editing may have role in regulation of apoptotic functions of this protein. It is thought that since the protein is p53 inducible that the protein may be pro-apopototic. Also ADAR1 knock out mice show increase in apoptosis which indicates editing may be involved in regulation of the cellular process.