Overview
| Uniprot ID | O00257 |
|---|
| Protein Name | E3 SUMO-protein ligase CBX4 |
|---|
| Gene Name | CBX4 |
|---|
| Organism | Homo sapiens |
|---|
Kla Sites from experimental identification
| Position |
Flanking peptide |
| 223 |
GAAGAPGKGSEKGPP |
| 227 |
APGKGSEKGPPNGMM |
Function
E3 SUMO-protein ligase that catalyzes sumoylation of target proteins by promoting the transfer of SUMO from the E2 enzyme to the substrate (PubMed:12679040, PubMed:22467880, PubMed:22825850). Also acts as a histone reader, which specifically recognizes and binds histone H3 trimethylated at 'Lys-9' and 'Lys-27' (H3K9me3 and H3K27me3, respectively) via its chromo domain (By similarity). Catalyzes sumoylation of HNRNPK, a p53/TP53 transcriptional coactivator, hence indirectly regulates p53/TP53 transcriptional activation resulting in p21/CDKN1A expression (PubMed:22825850). Acts as a regulator of brown adipocyte differentiation by mediating sumoylation of PRDM16, thereby preventing PRDM16 ubiquitination and degradation (By similarity). Monosumoylates ZNF131 (PubMed:22467880). Component of a Polycomb group (PcG) multiprotein PRC1-like complex, a complex class required to maintain the transcriptionally repressive state of many genes, including Hox genes, throughout development (PubMed:12167701, PubMed:19636380, PubMed:21282530). PcG PRC1 complex acts via chromatin remodeling and modification of histones; it mediates monoubiquitination of histone H2A 'Lys-119', rendering chromatin heritably changed in its expressibility (PubMed:12167701, PubMed:19636380, PubMed:21282530). Plays a role in the lineage differentiation of the germ layers in embryonic development (By similarity)
Protein Sequence
10
MELPAVGEHV
20
FAVESIEKKR
30
IRKGRVEYLV
40
KWRGWSPKYN
50
TWEPEENILD
60
PRLLIAFQNR
70
ERQEQLMGYR
80
KRGPKPKPLV
90
VQVPTFARRS
100
NVLTGLQDSS
110
TDNRAKLDLG
120
AQGKGQGHQY
130
ELNSKKHHQY
140
QPHSKERAGK
150
PPPPGKSGKY
160
YYQLNSKKHH
170
PYQPDPKMYD
180
LQYQGGHKEA
190
PSPTCPDLGA
200
KSHPPDKWAQ
210
GAGAKGYLGA
220
VKPLAGAAGA
230
PGKGSEKGPP
240
NGMMPAPKEA
250
VTGNGIGGKM
260
KIVKNKNKNG
270
RIVIVMSKYM
280
ENGMQAVKIK
290
SGEVAEGEAR
300
SPSHKKRAAD
310
ERHPPADRTF
320
KKAAGAEEKK
330
VEAPPKRREE
340
EVSGVSDPQP
350
QDAGSRKLSP
360
TKEAFGEQPL
370
QLTTKPDLLA
380
WDPARNTHPP
390
SHHPHPHPHH
400
HHHHHHHHHH
410
AVGLNLSHVR
420
KRCLSETHGE
430
REPCKKRLTA
440
RSISTPTCLG
450
GSPAAERPAD
460
LPPAAALPQP
470
EVILLDSDLD
480
EPIDLRCVKT
490
RSEAGEPPSS
500
LQVKPETPAS
510
AAVAVAAAAA
520
PTTTAEKPPA
530
EAQDEPAESL
540
SEFKPFFGNI
550
IITDVTANCL
560
TVTFKEYVTV
Gene Ontology
| Classification |
GO ID |
Description |
| Cellular Component |
GO:0000785 |
chromatin |
| Cellular Component |
GO:0016604 |
nuclear body |
| Cellular Component |
GO:0016607 |
nuclear speck |
| Cellular Component |
GO:0005654 |
nucleoplasm |
| Cellular Component |
GO:0005634 |
nucleus |
| Cellular Component |
GO:0031519 |
PcG protein complex |
| Cellular Component |
GO:0035102 |
PRC1 complex |
| Molecular Function |
GO:0003682 |
chromatin binding |
| Molecular Function |
GO:0019899 |
enzyme binding |
| Molecular Function |
GO:0061628 |
histone H3K27me3 reader activity |
| Molecular Function |
GO:0051219 |
phosphoprotein binding |
| Molecular Function |
GO:0003727 |
single-stranded RNA binding |
| Molecular Function |
GO:0032183 |
SUMO binding |
| Molecular Function |
GO:0061665 |
SUMO ligase activity |
| Molecular Function |
GO:0019789 |
SUMO transferase activity |
| Molecular Function |
GO:0000976 |
transcription cis-regulatory region binding |
| Molecular Function |
GO:0003714 |
transcription corepressor activity |
| Biological Process |
GO:0006351 |
DNA-templated transcription |
| Biological Process |
GO:0031507 |
heterochromatin formation |
| Biological Process |
GO:0043066 |
negative regulation of apoptotic process |
| Biological Process |
GO:0045892 |
negative regulation of DNA-templated transcription |
| Biological Process |
GO:0032435 |
negative regulation of proteasomal ubiquitin-dependent protein catabolic process |
| Biological Process |
GO:0000122 |
negative regulation of transcription by RNA polymerase II |
| Biological Process |
GO:0090336 |
positive regulation of brown fat cell differentiation |
| Biological Process |
GO:0050821 |
protein stabilization |
| Biological Process |
GO:0016925 |
protein sumoylation |
Reference
[1] Wu Q, Li Z, Gong T, Zheng X, Zhou X et al.. Porphyromonas gingivalis infection induces lysine lactylation reprogramming in human umbilical vein endothelial cells.. Front Cell Infect Microbiol 16:1706727. 2026. PMID: 41696360.