Q6PI79 (H33_XENLA) Reviewed, UniProtKB/Swiss-Prot
Last modified October 16, 2013. Version 77. History...
Names and origin
|Sequence length||136 AA.|
|Sequence processing||The displayed sequence is further processed into a mature form.|
|Protein existence||Evidence at protein level|
General annotation (Comments)
Variant histone H3 which replaces conventional H3 in a wide range of nucleosomes in active genes. Constitutes the predominant form of histone H3 in non-dividing cells and is incorporated into chromatin independently of DNA synthesis. Deposited at sites of nucleosomal displacement throughout transcribed genes, suggesting that it represents an epigenetic imprint of transcriptionally active chromatin. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling.
The nucleosome is a histone octamer containing two molecules each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and two H2A-H2B heterodimers. The octamer wraps approximately 147 bp of DNA.
Expressed during S phase, then expression strongly decreases as cell division slows down during the process of differentiation.
Acetylation is generally linked to gene activation. Acetylation on Lys-19 (H3K18ac) and Lys-24 (H3K24ac) favors methylation at Arg-18 (H3R17me). Acetylation at Lys-123 (H3K122ac) by EP300/p300 plays a central role in chromatin structure: localizes at the surface of the histone octamer and stimulates transcription, possibly by promoting nucleosome instability. Ref.2
Asymmetric dimethylation at Arg-18 (H3R17me2a) is linked to gene activation. Asymmetric dimethylation at Arg-3 (H3R2me2a) by prmt6 is linked to gene repression and is mutually exclusive with H3 Lys-5 methylation (H3K4me2 and H3K4me3). H3R2me2a is present at the 3' of genes regardless of their transcription state and is enriched on inactive promoters, while it is absent on active promoters By similarity.
Specifically enriched in modifications associated with active chromatin such as methylation at Lys-5 (H3K4me), Lys-37 (H3K36me) and Lys-80 (H3K79me) are linked to gene activation. Methylation at Lys-5 (H3K4me) facilitates subsequent acetylation of H3 and H4. Methylation at Lys-80 (H3K79me) is associated with DNA double-strand break (DSB) responses and is a specific target for tp53bp1. Methylation at Lys-10 (H3K9me) and Lys-28 (H3K27me) are linked to gene repression. Methylation at Lys-10 (H3K9me) is a specific target for HP1 proteins (cbx1, cbx3 and cbx5) and prevents subsequent phosphorylation at Ser-11 (H3S10ph) and acetylation of H3 and H4. Methylation at Lys-5 (H3K4me) and Lys-80 (H3K79me) require preliminary monoubiquitination of H2B at 'Lys-120' By similarity. Ref.2
Phosphorylated at Thr-4 (H3T3ph) by gsg2/haspin during prophase and dephosphorylated during anaphase. Phosphorylation at Ser-11 (H3S10ph) by aurkb is crucial for chromosome condensation and cell-cycle progression during mitosis and meiosis. In addition phosphorylation at Ser-11 (H3S10ph) by rps6ka4 and rps6ka5 is important during interphase because it enables the transcription of genes following external stimulation, like mitogens, stress, growth factors or UV irradiation and result in the activation of genes, such as c-fos and c-jun. Phosphorylation at Ser-11 (H3S10ph), which is linked to gene activation, prevents methylation at Lys-10 (H3K9me) but facilitates acetylation of H3 and H4. Phosphorylation at Ser-11 (H3S10ph) by aurkb mediates the dissociation of HP1 proteins (cbx1, cbx3 and cbx5) from heterochromatin. Phosphorylation at Ser-11 (H3S10ph) is also an essential regulatory mechanism for neoplastic cell transformation. Phosphorylated at Ser-29 (H3S28ph) by mltk isoform 1 rps6ka5 or aurkb during mitosis or upon ultraviolet B irradiation. Phosphorylation at Thr-7 (H3T6ph) by prkcb is a specific tag for epigenetic transcriptional activation that prevents demethylation of Lys-5 (H3K4me) by lsd1/kdm1a. At centromeres, specifically phosphorylated at Thr-12 (H3T11ph) from prophase to early anaphase, by dapk3 and pkn1. Phosphorylation at Thr-12 (H3T11ph) by pkn1 is a specific tag for epigenetic transcriptional activation that promotes demethylation of Lys-10 (H3K9me) by kdm4c/jmjd2c. Phosphorylation at Tyr-42 (H3Y41ph) by jak2 promotes exclusion of cbx5 (HP1 alpha) from chromatin. Phosphorylation on Ser-32 (H3S31ph) is specific to regions bordering centromeres in metaphase chromosomes By similarity. Ref.2
Monoubiquitinated by rag1 in lymphoid cells, monoubiquitination is required for V(D)J recombination By similarity.
Lysine deamination at Lys-5 (H3K4all) to form allysine only takes place on H3K4me3 and results in gene repression By similarity.
Belongs to the histone H3 family.
|Gene Ontology (GO)|
Inferred from electronic annotation. Source: InterPro
Inferred from electronic annotation. Source: UniProtKB-KWnucleus
Inferred from electronic annotation. Source: UniProtKB-SubCell
Inferred from electronic annotation. Source: UniProtKB-KW
|Complete GO annotation...|
Sequence annotation (Features)
|Feature key||Position(s)||Length||Description||Graphical view||Feature identifier|
|Initiator methionine||1||1||Removed By similarity|
|Chain||2 – 136||135||Histone H3.3||PRO_0000253957|
Amino acid modifications
|Modified residue||3||1||Asymmetric dimethylarginine; by PRMT6 By similarity|
|Modified residue||4||1||Phosphothreonine; by GSG2 By similarity|
|Modified residue||5||1||Allysine; alternate By similarity|
|Modified residue||5||1||N6,N6,N6-trimethyllysine; alternate Ref.2|
|Modified residue||5||1||N6,N6-dimethyllysine; alternate Ref.2|
|Modified residue||5||1||N6-acetyllysine; alternate By similarity|
|Modified residue||5||1||N6-methyllysine; alternate Ref.2|
|Modified residue||7||1||Phosphothreonine; by PKC By similarity|
|Modified residue||10||1||N6-methylated lysine Ref.2|
|Modified residue||11||1||Phosphoserine; by AURKB, AURKC, RPS6KA3, RPS6KA4 and RPS6KA5 By similarity|
|Modified residue||12||1||Phosphothreonine; by PKC By similarity|
|Modified residue||15||1||N6-acetyllysine Ref.2|
|Modified residue||18||1||Asymmetric dimethylarginine Ref.2|
|Modified residue||19||1||N6-acetyllysine; alternate By similarity|
|Modified residue||19||1||N6-methylated lysine; alternate By similarity|
|Modified residue||24||1||N6-acetyllysine By similarity|
|Modified residue||28||1||N6-acetyllysine; alternate By similarity|
|Modified residue||28||1||N6-methylated lysine; alternate By similarity|
|Modified residue||29||1||Phosphoserine; by AURKB, AURKC and RPS6KA5 By similarity|
|Modified residue||37||1||N6-acetyllysine; alternate By similarity|
|Modified residue||37||1||N6-methylated lysine; alternate By similarity|
|Modified residue||42||1||Phosphotyrosine By similarity|
|Modified residue||58||1||Phosphoserine By similarity|
|Modified residue||65||1||N6-methylated lysine By similarity|
|Modified residue||80||1||N6-methylated lysine By similarity|
|Modified residue||81||1||Phosphothreonine By similarity|
|Modified residue||116||1||N6-acetyllysine By similarity|
|Modified residue||123||1||N6-acetyllysine; alternate By similarity|
|Modified residue||123||1||N6-methyllysine; alternate By similarity|
|||NIH - Xenopus Gene Collection (XGC) project|
Submitted (SEP-2006) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
|||"Involvement of histone methylation and phosphorylation in regulation of transcription by thyroid hormone receptor."|
Li J., Lin Q., Yoon H.-G., Huang Z.-Q., Strahl B.D., Allis C.D., Wong J.
Mol. Cell. Biol. 22:5688-5697(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: METHYLATION AT LYS-5; LYS-10 AND ARG-18, PHOSPHORYLATION AT SER-11, ACETYLATION AT LYS-15.
|BC041218 mRNA. Translation: AAH41218.1.|
BC042290 mRNA. Translation: AAH42290.1.
BC042309 mRNA. Translation: AAH42309.1.
BC070966 mRNA. Translation: AAH70966.1.
BC074158 mRNA. Translation: AAH74158.1.
BC106302 mRNA. Translation: AAI06303.1.
BC123120 mRNA. Translation: AAI23121.1.
|RefSeq||NP_001079375.1. NM_001085906.1. |
3D structure databases
|SMR||Q6PI79. Positions 17-136. |
Protocols and materials databases
Genome annotation databases
|Xenbase||XB-GENE-488762. h3f3b. |
Family and domain databases
|Gene3D||18.104.22.168. 1 hit. |
|InterPro||IPR009072. Histone-fold. |
|PANTHER||PTHR11426. PTHR11426. 1 hit. |
|Pfam||PF00125. Histone. 1 hit. |
|PRINTS||PR00622. HISTONEH3. |
|SMART||SM00428. H3. 1 hit. |
|SUPFAM||SSF47113. SSF47113. 1 hit. |
|PROSITE||PS00322. HISTONE_H3_1. 1 hit. |
PS00959. HISTONE_H3_2. 1 hit.
|Accession||Primary (citable) accession number: Q6PI79|
Secondary accession number(s): Q05AX9
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Chordata Protein Annotation Program|
Index of protein domains and families