NCAPH
Protein-coding gene in the species Homo sapiens
From Wikipedia, the free encyclopedia
Condensin complex subunit 2 also known as chromosome-associated protein H (CAP-H) or non-SMC condensin I complex subunit H (NCAPH) is a protein that in humans is encoded by the NCAPH gene.[5][6] CAP-H is a subunit of condensin I, a large protein complex involved in chromosome condensation. Abnormal expression of NCAPH may be linked to various types of carcinogenesis as a prognostic indicator.[7]
| NCAPH | |||||||||||||||||||||||||||||||||||||||||||||||||||
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| Aliases | NCAPH, BRRN1, CAP-H, non-SMC condensin I complex subunit H, MCPH23, CAPH | ||||||||||||||||||||||||||||||||||||||||||||||||||
| External IDs | OMIM: 602332; MGI: 2444777; HomoloGene: 133986; GeneCards: NCAPH; OMA:NCAPH - orthologs | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Function
CAP-H is a member of the barr protein family and a regulatory subunit of the condensin complex. This complex is required for the conversion of interphase chromatin into condensed chromosomes.[7] CAP-H is associated with mitotic chromosomes, except during the early phase of chromosome condensation. During interphase, the protein has a distinct punctate nucleolar localization.[6]
Structure and interactions
As one of the main subunits in the highly conserved SMC condensin I complex in eukaryotes, NCAPH associates with NCAPG, NCAPD2, and the N and C termini of the SMC-4 and SMC-2 proteins. NCAPH creates a bridge between the head groups of the SMC proteins and functions as a kleisin protein.[7][8][9]
The interaction between NCAPH and the globular ATPase head binding sites of the C terminus and N terminus of the SMC heterodimer allows condensin to have dynamic properties. The C terminus end of NCAPH assumes a winged-helix conformation, which then associates with either head group of the SMC protein. At the opposite end of the kleisin protein, the N terminus associates with proximal coiled coil of the other SMC protein, and creates a helical bundle.[8] This attribute enables the condensin complex to have open and closed conformations in order to associate with chromatin and aid in proper folding of DNA in the condensation process.[9][10]
Studies suggest that the sub-complex formed between NCAPH and NCAPG is critical for interactions with single-stranded DNA and double-stranded DNA to assist mitotic chromosome assembly in eukaryotes.[9]
Clinical significance
NCAPH may be used as a prognostic indicator of carcinogenesis in humans, as the abnormal over-expression of NCAPH is observed in many cancer types.[11]
Studies show that, in prostate cancer,[12] nasopharyngeal carcinoma,[13] hepatocellular carcinoma,[14] and breast cancers,[15] NCAPH is commonly over-expressed, and may be used as a biomarker for various cancer types and a viable prognostic factor for identification and potential drug targeting.[12]
In colon cancer, NCAPH is shown to be higher expressed in cancerous cells compared to non-cancerous epithelial cells. supplementally, when NCAPH is depleted, studies show a decrease in colon cancer cell proliferation.[11][16] Studies show that high expression of NCAPH in colon cancer and non-small cell lung cancer patients had an increased survival rate than those with a lower expression of NCAPH.[16]
