Nucleosome assembly protein 1-like 4 (NAP1L4)
The protein contains 375 amino acids for an estimated molecular weight of 42823 Da.
Acts as histone chaperone in nucleosome assembly. (updated: Oct. 25, 2017)
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.
- 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.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
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 601651
Nucleosome assembly protein 1-like 4; nap1l4
Nucleosome assembly protein 2-like; nap2l
Nap2
CLONING
Hu et al. (1996) used a positional cloning approach to isolate a gene which is located 100 kb centromeric to the proximal Beckwith-Wiedemann breakpoint cluster region (BWS; 130650) on chromosome 11p15. This gene is homologous to the yeast nucleosome assembly protein NAP1 (164060). The authors designated the new gene NAP2. They demonstrated that this gene shows biallelic expression in all tissues tested and that it therefore diverges in its expression from IGF2 (147470), H19 (103280), and p57(KIP2) (600856), which also map to 11p15.5 in the vicinity of the BWS gene. The NAP2 gene encodes a highly acidic protein of 375 amino acids.GENE STRUCTURE
Rodriguez et al. (1997) reported that the NAP1L4 gene consists of 14 exons and spans approximately 30.5 kb. A 1,200-bp 3-prime untranslated region was present.MAPPING
Hu et al. (1996) mapped the NAP1L4 gene to chromosome 11p15.5.GENE FUNCTION
Histones are thought to play a key role in regulating gene expression at the level of DNA packaging. The deduced amino acid sequence of NAP2 indicates that it is a protein with a potential nuclear localization motif and 2 clusters of highly acidic residues. By functional analysis of recombinant NAP2 protein purified from Escherichia coli, Rodriguez et al. (1997) found that this protein can interact with both core and linker histones (see 142709). They demonstrated that recombinant NAP2 can transfer histones onto naked DNA templates. Subcellular localization studies of NAP2 indicated that it can shuttle between the cytoplasm and nucleus, suggesting a role as a histone chaperone. NAP1 and NAP2 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.MOLECULAR GENETICS
NAP1L4 maps to a region implicated in Wilms tumor etiology (see 194071). Rodriguez et al. (1997) analyzed the gene encoding NAP2 for mutations and found no evidence of nonsense, frameshift, or deletion mutations. Their findings, coupled with tumor suppression assays in Wilms tumor cells, did not support a role for NAP2 in the etiology of that neoplasm. ... More on the omim web site
Feb. 10, 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 601651 was added.