Nucleosome assembly protein 1-like 1 (NAP1L1)
The protein contains 391 amino acids for an estimated molecular weight of 45374 Da.
Histone chaperone that plays a role in the nuclear import of H2A-H2B and nucleosome assembly (PubMed:20002496, PubMed:26841755). Participates also in several important DNA repair mechanisms: greatly enhances ERCC6-mediated chromatin remodeling which is essential for transcription-coupled nucleotide excision DNA repair (PubMed:28369616). Stimulates also homologous recombination (HR) by RAD51 and RAD54 which is essential in mitotic DNA double strand break (DSB) repair (PubMed:24798879). Plays a key role in the regulation of embryonic neurogenesis (By similarity). Promotes the proliferation of neural progenitors and inhibits neuronal differentiation during cortical development (By similarity). Regulates neurogenesis via the modulation of RASSF10; regulates RASSF10 expression by promoting SETD1A-mediated H3K4 methylation at the RASSF10 promoter (By similarity).', '(Microbial infection) Positively regulates Epstein-Barr virus reactivation in epithelial cells through the induction of viral BZLF1 expression.', '(Microbial infection) Together with human herpesvirus 8 protein LANA1, assists the proper assembly of the nucleosome on the replicated viral DNA. (updated: Feb. 10, 2021)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
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The reference OMIM entry for this protein is 164060
Nucleosome assembly protein 1-like 1; nap1l1
Nap1; nap1l
Napi-related protein; nrp
Nucleosome assembly protein i-related protein
CLONING
From a human thymus cDNA library, Simon et al. (1994) isolated a cDNA encoding a protein with 54% amino acid similarity to yeast nucleosome assembly protein I (NAPI). The deduced amino acid sequence of the identified protein, designated NRP (for 'NAP-related protein'), has a potential 7-residue nuclear localization motif, 3 clusters of highly acidic residues, and other structural features found in various proteins implicated in chromatin formation. NRP transcript was detected in all human tissues and cell lines studied, but levels were somewhat increased in rapidly proliferating cells. This and other observations suggested to the authors that the NRP gene product participates in DNA replication and therefore plays an important role in the process of cell proliferation.GENE FUNCTION
Hajkova et al. (2008) studied epigenetic changes in primordial germ cells (PGCs) in the mouse lineage. They showed that the chromatin changes occur in 2 steps. The first changes in nascent PGCs at embryonic day 8.5 establish a distinctive chromatin signature that is reminiscent of pluripotency. Next, when PGCs are residing in the gonads, major changes occur in nuclear architecture accompanied by an extensive erasure of several histone modifications and exchange of histone variants. Furthermore, the histone chaperones HIRA (600237) and NAP1, which are implicated in histone exchange, accumulate in PGC nuclei undergoing reprogramming. Hajkova et al. (2008) therefore suggested that the mechanism of histone replacement is critical for these chromatin rearrangements to occur. The marked chromatin changes are intimately linked with genomewide DNA demethylation. On the basis of the timing of the observed events, Hajkova et al. (2008) proposed that if DNA demethylation entails a DNA repair-based mechanism, the evident histone replacement would represent a repair-induced response event rather than being a prerequisite. NAP1 and NAP2 (NAP1L4; 601651) facilitate nucleosome assembly by first depositing preformed tetramers made up of 2 molecules each of histones H3 (see 602810) and H4 (see 602822) onto DNA prior to the addition of tetramers made up of 2 molecules each of histones H2A (see 142720) and H2B (see 609904). Using recombinant human proteins in an in vitro nucleosome formation assay, Tachiwana et al. (2008) confirmed that both NAP1 and NAP2 promoted formation of nucleosomes containing the conventional histones H2A, H2B, H3.1 (see 602810), and H4. NAP1 could also promote nucleosome assembly with the H3 variants H3.2 (HIST2H3C; 142780), H3.3 (see 601128), and CENPA (117139), but not the testis-specific H3 variant H3T (HIST3H3; 602820). In contrast, NAP2 promoted nucleosome assembly with H3T, bound H3T/H4 tetramers efficiently, and was released from H3T/H4 tetramers in the presence of DNA. Mutation analysis revealed that a change of ala111, which is conserved among H3.1, H3.2, and H3.3, to val in H3T was responsible for the differential binding of these H3 variants to NAP1.BIOCHEMICAL FEATURES
Park and Luger (2006) resolved the crystal structure of yeast Nap1 to 3.0-angstrom resolution. They determined that a long alpha helix mediates homodimerization, and a domain containing both alpha helices and beta sheets mediates protein-protein interactions. A nuclear export sequence embedded in the dimerization helix is almost completely masked by an accessory domain containing several putative phosphorylation sites. Human NAP1 share ... More on the omim web site
Feb. 16, 2021: Protein entry updated
Automatic update: Entry updated from uniprot information.
Nov. 16, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 164060 was added.