Sin3A-associated protein, 30kDa, also known as SAP30, 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, respo ...

which in humans is encoded by the SAP30

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 ba ...

Function

Histone In biology, histones are highly basic proteins abundant in lysine and arginine residues that are found in eukaryotic cell nuclei. They act as spools around which DNA winds to create structural units called nucleosomes. Nucleosomes in turn are wr ...

acetylation : In organic chemistry, acetylation is an organic esterification reaction with acetic acid. It introduces an acetyl group into a chemical compound. Such compounds are termed ''acetate esters'' or simply '' acetates''. Deacetylation is the oppo ...

plays a key role in the regulation of eukaryotic gene expression. Histone acetylation and deacetylation are catalyzed by multisubunit complexes. The protein encoded by this gene is a component of the

histone deacetylase Histone deacetylases (, HDAC) are a class of enzymes that remove acetyl groups (O=C-CH3) from an ε-N-acetyl lysine amino acid on a histone, allowing the histones to wrap the DNA more tightly. This is important because DNA is wrapped around his ...

complex, which includes

SIN3A Paired amphipathic helix protein Sin3a is a protein that in humans is encoded by the ''SIN3A'' gene. Function The protein encoded by this gene is a transcriptional regulatory protein. It contains paired amphipathic helix (PAH) domains, which a ...

SAP18 Histone deacetylase complex subunit SAP18 is an enzyme that in humans is encoded by the ''SAP18'' gene. Function Histone acetylation plays a key role in the regulation of eukaryotic gene expression. Histone acetylation and deacetylation are cat ...

HDAC1 Histone deacetylase 1 (HDAC1) is an enzyme that in humans is encoded by the ''HDAC1'' gene. Function Histone acetylation and deacetylation, catalyzed by multisubunit complexes, play a key role in the regulation of eukaryotic gene expression. T ...

HDAC2 Histone deacetylase 2 (HDAC2) is an enzyme that in humans is encoded by the ''HDAC2'' gene. It belongs to the histone deacetylase class of enzymes responsible for the removal of acetyl groups from lysine residues at the N-terminal region of the co ...

, RbAp46,

RbAp48 #REDIRECT RBBP4 {{R from other capitalization ...

, and other polypeptides. This complex is active in deacetylating core histone octamers, but inactive in deacetylating nucleosomal histones. A pseudogene of this gene is located on chromosome 3. Mammals have one paralog of SAP30, named SAP30-like ( SAP30L), which shares 70% sequence identity with SAP30. SAP30 and SAP30L together constitute a well-conserved SAP30 protein family. Also SAP30L interacts with several components of the Sin3A corepressor complex and induces transcriptional repression via recruitment of Sin3A and histone deacetylases. Proteins of the SAP30 family (SAP30 proteins) have a functional

nucleolar The nucleolus (, plural: nucleoli ) is the largest structure in the nucleus of eukaryotic cells. It is best known as the site of ribosome biogenesis, which is the synthesis of ribosomes. The nucleolus also participates in the formation of s ...

localization signal and they are able to target Sin3A to the nucleolus. SAP30 proteins have sequence-independent contact with DNA by their N-terminal zinc-dependent module and their acidic central region contributes to histone and nucleosome interactions. The DNA binding of SAP30 proteins is regulated by the nuclear signalling lipids, phosphoinositides (PI). SAP30 proteins provide the first example in which the DNA and PIs seem to stand in a mutually antagonizing interrelationship in regard to their interaction with

zinc finger A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn2+) in order to stabilize the fold. It was originally coined to describe the finger-like appearance of a hypothesized struct ...

proteins and thus exemplifies the molecular mechanism how these lipids can contribute for gene regulation.

Interactions

SAP30 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 organizati ...

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Histone deacetylase 2 Histone deacetylase 2 (HDAC2) is an enzyme that in humans is encoded by the ''HDAC2'' gene. It belongs to the histone deacetylase class of enzymes responsible for the removal of acetyl groups from lysine residues at the N-terminal region of the c ...

, *

ING1 Inhibitor of growth protein 1 is a protein that in humans is encoded by the ''ING1'' gene. Function This gene encodes a tumor suppressor protein that can induce cell growth arrest and apoptosis. The encoded protein is a nuclear protein that ph ...

and *

Nuclear receptor co-repressor 1 The nuclear receptor co-repressor 1 also known as thyroid-hormone- and retinoic-acid-receptor-associated co-repressor 1 (TRAC-1) is a protein that in humans is encoded by the ''NCOR1'' gene. NCOR1 is a transcriptional coregulatory protein which c ...

, *

RBBP4 #REDIRECT RBBP4 {{R from other capitalization ...

, *

RBBP7 Histone-binding protein RBBP7 is a protein that in humans is encoded by the ''RBBP7'' gene. Function This protein is a ubiquitously expressed nuclear protein and belongs to a highly conserved subfamily of WD-repeat proteins. It is found among ...

, *

, and *

YY1 YY1 (Yin Yang 1) is a transcriptional repressor protein in humans that is encoded by the YY1 gene. Function YY1 is a ubiquitously distributed transcription factor belonging to the GLI-Kruppel class of zinc finger proteins. The protein is invo ...

Function

Interactions

References

Further reading