Kromatiinin koostumistekijöistä (Multiple Chromatin Assembly factors needed)

RCAF = Replication -Coupling Assembly Factor
ASF1 = Anti-Silencing Function 1 protein, component of RCAF-complex. 

https://www.ncbi.nlm.nih.gov/pubmed/10591219

Nature. 1999 Dec 2;402(6761):555-60.

The RCAF complex mediates chromatin assembly during DNA replication and repair.

Tyler JK¹, Adams CR, Chen SR, Kobayashi R, Kamakaka RT, Kadonaga JT.

Abstract

Chromatin assembly is a fundamental biological process that is essential for the replication and maintenance of the eukaryotic genome. In dividing cells, newly synthesized DNA is rapidly assembled into chromatin by the deposition of a tetramer of the histone proteins H3 and H4, followed by the deposition of two dimers of histones H2A and H2B to complete the nucleosome-the fundamental repeating unit of chromatin. Here we describe the identification, purification, cloning, and characterization of replication-coupling assembly factor (RCAF), a novel protein complex that facilitates the assembly of nucleosomes onto newly replicated DNA in vitro. RCAF comprises the Drosophila homologue of anti-silencing function 1 protein ASF1 and histones H3 and H4. The specific acetylation pattern of H3 and H4 in RCAF is identical to that of newly synthesized histones. Genetic analyses in Saccharomyces cerevisiae demonstrate that ASF1 is essential for normal cell cycle progression, and suggest that RCAF mediates chromatin assembly after DNA replication and the repair of double-strand DNA damage in vivo.

ASF1A (6q22.31) , anti-silencing function IA histone chaperone, CCGI-interacting factor -A, hCIA, HSPC146.  https://www.ncbi.nlm.nih.gov/gene/25842
-ASF1A promotes NHEJ
-Compatible with MMR is CAF1- and ASF1A.H3-H4-dependent deposition on  H3-H4 tetramers   and protects  the discontinuous daughter strand from unnecessary degradatio  by MMR machinery.
 ASF1A is regulated/degradated  by UBE2 RAD6A/B - E3 Ubiquitinligase MDM2- machinery. 

CAF1A, (19p13.3) 
 CAF1P150, hp 150, CTB-50L17.7, Chromatin Assemly Factor 1 p150 subunit
https://www.ncbi.nlm.nih.gov/gene/10036
 CAF1; P150; CAF-1; CAF1B.

Summary

Chromatin assembly factor I (CAF1) is a nuclear complex consisting of p50, p60 (CHAF1B; MIM 601245), and p150 (CHAF1A) subunits that assembles histone octamers onto replicating DNA in vitro (Kaufman et al., 1995 [PubMed 7600578]).[supplied by OMIM, Mar 2008]

Expression

Broad expression in bone marrow (RPKM 7.4), testis (RPKM 6.1) and 24 other tissues See more

Orthologs mouse all

 

 CAF1B , (21q22.12-q22.13)

https://www.ncbi.nlm.nih.gov/gene/8208 

Also known as

CAF1; MPP7; CAF-1; CAF1A; CAF1P60; CAF-IP60; MPHOSPH7

Summary

Chromatin assembly factor I (CAF-I) is required for the assembly of histone octamers onto newly-replicated DNA. CAF-I is composed of three protein subunits, p50, p60, and p150. The protein encoded by this gene corresponds to the p60 subunit and is required for chromatin assembly after replication. The encoded protein is differentially phosphorylated in a cell cycle-dependent manner. In addition, it is normally found in the nucleus except during mitosis, when it is released into the cytoplasm. This protein is a member of the WD-repeat HIR1 family and may also be involved in DNA repair. [provided by RefSeq, Jul 2008]

Expression

Broad expression in bone marrow (RPKM 2.7), testis (RPKM 2.6) and 25 other tissues See more

Orthologs

mouse all

 

(Tuo kolmas alayksikkö  p50 tai p48, saattaa olla histoniasetyltransferaasityyppi-, joka  asetyloi H2B histonia, siis ainakin Rattus Norvegicuksessa ja se on p48 kokoa mahdollisesti.  Arvelen vain, kun en löydä ihmisortologeista tuon kolmannen alayksikön geeniä  nyt.  Rotalla se oli kromosomissa 17.)   

 

 ( Nämä CAF1, CAF2 ja CAF3 Chromatin Assembly Factors  ovat alayksikköjä ja muodostavat komplkesin. Alayksiköt taas ovat eri kromosomeissa.

Löysin CAF1A  ja se on p150 alayksikköä vasttaava. Siten  CAF21B vastaa  alayksikköä p60.

Kompleksin nimenä sanotaan olevan CAC Toisessa paikassa taas on  sanottuettä nämä ovat geenejä CAC1, CAC2, CAC3 ainkin alemmissa organisemissa. 

Yhdestä hiivasta siten etsin tuota  cac-3 ja sen nimenä sattuun olemaan histoniacetyltransferase type 2 subunit B. Sitten ajatelein että ylemmillä voi olla ortologia tuolla hakusanalla. Lopulta löysin rotalta tuon entsyymin kr. . 17.  Hain koolla  "p48". Entsyymi on  Histoni H2B kompleksiin kuuluva   histoniasetylaasi . Sinänsä loogista. Tämä on vain pohdintaani. Kovin on mosaiikasta koottu tuo replikaatiohaarukan työn täsmällisyys- kyllä siinä ihmiskunta on  saada tuhannet vuodet  koulittu nykyiseen suhteelliseen konservoituneeseen hahmoonsa.) Mikähän nykyihmisen nimi on 1000 vuoden päästä? (Homo Unitednationensis post-WWII)