HELLS | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Aliases | HELLS , LSH, PASG, SMARCA6, Nbla10143, ICF4, helicase, lymphoid-specific, helicase, lymphoid specific | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | OMIM: 603946; MGI: 106209; HomoloGene: 50037; GeneCards: HELLS; OMA:HELLS - orthologs | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Wikidata | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Lymphoid-specific helicase (Lsh) is a member of the SNF2 helicase family of chromatin remodeling proteins that in humans is encoded by the HELLS gene.
The HELLS gene has proved to play critical roles in DNA methylation, chromatin packaging, control of Hox genes, stem cell proliferation, and developing lymphoid tissue.
In a developing embryo, epigenetic programming is controlled through the mechanisms of DNA methylation and chromatin organization. These processes are the master regulators that determine which genes are turned on or off throughout development. Lsh, a protein encoded by the HELLS gene is a major regulator of methylation patterns and thus crucial to normal fetal development.
Mutations and knockouts of the HELLS gene severely disrupts the process of fetal programming. In mice, knockout of HELLS gene resulted in death of embryos at birth and caused embryonic growth retardation. In humans, hypomethylation caused by a mutation in the HELLS gene is linked to Immunodeficiency-centromeric instability-facial anomalies syndrome 4 (ICF4). This is a rare disease that causes immunodeficiency, facial anomalies, growth retardation, failure to thrive, and psychomotor retardation. The adverse effects due to the absence and mutation of the HELLS gene is a result of the extensive loss of genomic wide methylation and the abnormal expression of repeat sequences. The disruption in methylation patterns can cause the silencing of genes or the over-expression of genes, leading to abnormal and in some cases fatal developmental consequences.
This gene encodes a lymphoid-specific helicase. Other helicases function in processes involving DNA strand separation, including replication, repair, recombination, and transcription. This protein is thought to be involved with cellular proliferation and may play a role in leukemogenesis. Alternatively spliced transcript variants have been described, but their biological validity has not been determined. [5]
Chromatin remodeling is the dynamic modification of chromatin architecture to allow access of condensed genomic DNA to the regulatory transcription machinery proteins, and thereby control gene expression. Such remodeling is principally carried out by 1) covalent histone modifications by specific enzymes, e.g., histone acetyltransferases (HATs), deacetylases, methyltransferases, and kinases, and 2) ATP-dependent chromatin remodeling complexes which either move, eject or restructure nucleosomes. Besides actively regulating gene expression, dynamic remodeling of chromatin imparts an epigenetic regulatory role in several key biological processes, egg cells DNA replication and repair; apoptosis; chromosome segregation as well as development and pluripotency. Aberrations in chromatin remodeling proteins are found to be associated with human diseases, including cancer. Targeting chromatin remodeling pathways is currently evolving as a major therapeutic strategy in the treatment of several cancers.
Homeobox protein Hox-B7 is a protein that in humans is encoded by the HOXB7 gene.
Transcriptional regulator ATRX also known as ATP-dependent helicase ATRX, X-linked helicase II, or X-linked nuclear protein (XNP) is a protein that in humans is encoded by the ATRX gene.
AT-rich interactive domain-containing protein 1A is a protein that in humans is encoded by the ARID1A gene.
Homeobox protein Meis1 is a protein that in humans is encoded by the MEIS1 gene.
Chromodomain-helicase-DNA-binding protein 3 is an enzyme that in humans is encoded by the CHD3 gene.
Chromodomain-helicase-DNA-binding protein 4 is an enzyme that in humans is encoded by the CHD4 gene. CHD4 is the core nucleosome-remodelling component of the Nucleosome Remodelling and Deacetylase (NuRD) complex.
Homeobox protein Hox-A7 is a protein that in humans is encoded by the HOXA7 gene.
Homeobox protein Hox-B3 is a protein that in humans is encoded by the HOXB3 gene.
Lysine N-methyltransferase 2C (KMT2C) also known as myeloid/lymphoid or mixed-lineage leukemia protein 3 (MLL3) is an enzyme that in humans is encoded by the KMT2C gene.
Probable helicase senataxin is an enzyme that in humans is encoded by the SETX gene.
Helicase-like transcription factor is an enzyme that in humans is encoded by the HLTF gene.
Homeobox protein Hox-A3 is a protein that in humans is encoded by the HOXA3 gene.
B-cell lymphoma/leukemia 11A is a protein that in humans is encoded by the BCL11A gene.
Helicase SRCAP is an enzyme that in humans is encoded by the SRCAP gene.
Homeobox protein Hox-D1 is a protein that in humans is encoded by the HOXD1 gene.
Chromodomain-helicase-DNA-binding protein 8 is an enzyme that in humans is encoded by the CHD8 gene.
Chromodomain-helicase-DNA-binding protein 1-like (ALC1) is an enzyme that in humans is encoded by the CHD1L gene. It has been implicated in chromatin remodeling and DNA relaxation process required for DNA replication, repair and transcription. The ALC1 comprises ATPase domain and macro domain. On the basis of homology within the ATPase domain, ALC1 belongs to Snf2 family.
SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A-like protein 1 is a protein that in humans is encoded by the SMARCAL1 gene.
H3K27me3 is an epigenetic modification to the DNA packaging protein Histone H3. It is a mark that indicates the tri-methylation of lysine 27 on histone H3 protein.