DCLRE1B

DNA cross-link repair 1B protein is a protein that in humans is encoded by the DCLRE1B gene.^[5]

DCLRE1B
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 3BUA, 5AHO
Identifiers
Aliases	DCLRE1B, APOLLO, SNM1B, SNMIB, DNA cross-link repair 1B
External IDs	OMIM: 609683; MGI: 2156057; HomoloGene: 32553; GeneCards: DCLRE1B; OMA:DCLRE1B - orthologs
Gene location (Human) Chr. Chromosome 1 (human)[1] Band 1p13.2 Start 113,905,213 bp[1] End 113,914,086 bp[1]
Gene location (Mouse) Chr. Chromosome 3 (mouse)[2] Band 3|3 F2.2 Start 103,707,921 bp[2] End 103,716,760 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in secondary oocyte gonad ganglionic eminence ventricular zone monocyte skin of hip testicle granulocyte bone marrow trabecular bone Top expressed in granulocyte blood otic vesicle cumulus cell yolk sac endocardial cushion external carotid artery abdominal wall ventricular zone tail of embryo More reference expression data BioGPS More reference expression data
Gene ontology Molecular function 5'-3' exonuclease activity 5'-3' exodeoxyribonuclease activity damaged DNA binding protein binding nuclease activity exonuclease activity hydrolase activity protein homodimerization activity protein-containing complex binding Cellular component cytoplasm centrosome chromosome microtubule organizing center telomere cytoskeleton nucleus nucleoplasm nuclear body Biological process cell cycle checkpoint signaling protection from non-homologous end joining at telomere telomeric 3' overhang formation cellular response to DNA damage stimulus double-strand break repair via nonhomologous end joining telomere maintenance telomeric loop formation DNA repair nucleic acid phosphodiester bond hydrolysis telomere maintenance via telomere lengthening telomere capping interstrand cross-link repair mitotic cell cycle checkpoint signaling Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 64858 140917 Ensembl ENSG00000118655 ENSMUSG00000027845 UniProt Q9H816 Q8C7W7 RefSeq (mRNA) NM_022836 NM_001319946 NM_001319947 NM_001363690 NM_001363691 NM_001025312 NM_133865 RefSeq (protein) NP_001306875 NP_001306876 NP_073747 NP_001350619 NP_001350620 NP_001020483 NP_598626 Location (UCSC) Chr 1: 113.91 – 113.91 Mb Chr 3: 103.71 – 103.72 Mb PubMed search [3] [4]
Wikidata
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DNA interstrand cross-links prevent strand separation, thereby physically blocking transcription, replication, and segregation of DNA. DCLRE1B is one of several evolutionarily conserved genes involved in repair of interstrand cross-links (Dronkert et al., 2000).[supplied by OMIM]^[5]

Function

The DCLRE1B/SNM1B/Apollo protein is a repair exonuclease that digests double-stranded and single-stranded DNA with a 5’ to 3’ directionality.^[6]

Using an SNM1B/Apollo knockout mouse model, evidence was obtained that SNM1B/Apollo protein is required to protect telomeres against illegitimate non-homologous end joining that can result in genomic instability and consequently in multi-organ developmental failure.^[7]

In a human patient with Hoyeraal-Hreidarsson syndrome, a dominant negative mutation in the SNM1B/Apollo gene was discovered.^[8] This mutation hampered the proper replication of telomeres, leading to major telomeric dysfunction and cellular senescence. SNM1B/Apollo protein appears to be a crucial factor in telomere maintenance, independent of its function in repairing DNA inter-strand crosslinks.^[8]