KPNA2 / importin-alpha-1 (P52292) - the classical NLS receptor in the pan-MLL-fusion core, and the ONLY karyopherin of any kind in the whole 960-protein network
also called KPNA2 · importin subunit alpha-1 · importin alpha-1 · karyopherin alpha 2 · RCH1 · SRP1 · SRP1-alpha · RAG cohort protein 1
KPNA2 is the adaptor that recognises the short address tag telling a protein to go into the nucleus, and hands it to the transport machinery. It co-purifies with every MLL fusion tested - and strikingly, no other transport protein does, not even the importin-beta partner it normally works with.
The same thing, for a scientist
KPNA2 (P52292, 529 aa) is importin-alpha-1, the adaptor of the classical nuclear import pathway: it binds monopartite and bipartite NLSs through an armadillo-repeat surface and is delivered to the pore by importin-beta, which relieves an autoinhibitory internal NLS in its own IBB domain. In Skucha 2018 it co-purified with all seven MLL fusions, MLL-AF4 at p = 0.0167 (5|2), negative control 0|0. The fact that makes this row informative rather than generic is a measured absence: **KPNA2 is the only karyopherin in the 960-protein network.** KPNB1, RAN, RCC1, KPNA1, KPNA3, KPNA4, IPO7 and TNPO1 are all absent at any n. Bulk import machinery did not come along; one adaptor did. And that adaptor has a documented, published relationship with two other pan-fusion members of this same set - NUP50 binds importin-alpha directly, and the Nup153 distal-tail site that recruits NUP50 is importin-alpha-dependent. Nuclear transport is one of the two processes Skucha et al. name in their own discussion as newly associated with MLL fusions by this network.
The Skucha row, stated in full
7 of 7 fusions. MLL-AF1p 0.0078 (5|3), MLL-AF4 0.0167 (5|2), MLL-AF9 0.0095 (8|7), MLL-CBP 0.0012 (7|8), MLL-EEN 0.0137 (7|8), MLL-ENL 0.0056 (11|7), MLL-GAS7 0.0114 (8|7); negative control 0|0 1. Another very even row - all seven baits between 0.0012 and 0.0167, total spectra 7 to 18, and KPNA2 has the lowest absolute spectral depth in the tranche (7 total under MLL-AF4). This is a shallow, uniform, clean-control row.
The measured absence that makes this interesting
Counted by this beat from the 960-protein table, 2026-09-21. Present: KPNA2 (7 of 7 fusions). Absent at any n: KPNB1, RAN, RCC1, KPNA1, KPNA3, KPNA4, KPNA6, IPO7, TNPO1, RANBP2, NUTF2. The only Ran-family proteins anywhere in the network are RANBP9 (3 of 7), RANBP1 (1) and RANBP10 (1), and RANBP9/RANBP10 are CTLH-complex scaffolds rather than transport factors - the CTLH complex being something Skucha et al. flag as an MLL-GAS7-specific interaction.
So the classical import receptor is present without importin-beta and without Ran. That is not what a nuclear-transport contamination looks like. A carry-over of soluble import machinery would bring importin-beta, which is abundant and sticky, and would bring more than one alpha isoform. What is here is a single adaptor - one that binds NLSs, and one that also binds NUP50 and the NUP153 distal tail, both of which are also in this network.
What KPNA2 does
The 2.5 A crystal structure of mammalian importin-alpha shows a large C-terminal armadillo-repeat domain and a less structured N-terminal importin-beta-binding domain containing an internal NLS occupying the NLS-binding site - the autoinhibitory switch between the cytoplasmic high-affinity form and the nuclear low-affinity form, with importin-beta converting one to the other by binding a site overlapping the autoinhibitory sequence 2. Six alpha importins exist in humans against one importin-beta, and specificity is not a property of the NLS alone: swapping the NLSs of RCC1 (preferentially imported by importin-alpha-3) and nucleoplasmin showed that both the NLS and the protein context contribute to which alpha importin transports a cargo 3. That is the reason a single alpha isoform in a purification is a substantive observation rather than a generic transport signal.
The three-way relationship with NUP50 and NUP153, which are also in this network
The Nup153-Nup50 partnership has a dual interface: one site in Nup153's unique N-terminal region critical for Nup50's pore localisation, and a second site at Nup153's distal tail that is importin-alpha-dependent, so Nup153 provides a local environment bringing Nup50 and importin-alpha together 4. In this network NUP50 is 7 of 7, TPR is 7 of 7, NUP153 is 4 of 7 and KPNA2 is 7 of 7. Four proteins that are documented to associate with each other at the nuclear basket, all recovered together.
Read one way that is a coherent nuclear-basket-plus-adaptor signature. Read the other way it is a warning: three or four proteins that bind each other will co-purify as a unit with anything that pulls down one of them, so this is plausibly ONE recovery reported four times, not four independent associations with the fusion. This entry records both readings and does not choose.
The KMT2A import question that nobody has asked
(importin OR importins OR karyopherin)[tiab] against the KMT2A clause returns exactly 1 record, and it is about KPNB1 and HMGB2 in AML - not KPNA2 and not a KMT2A fusion. KPNA2[tiab] OR "karyopherin alpha 2"[tiab] OR "importin alpha-1"[tiab] against the same clause returns 0.
And there is a specific gap this touches. This graph carries localization-nuclear-import-determinant-maps-to-the-at-hook-region - the KMT2A N-terminal region that determines nuclear import, which is retained in every fusion in Skucha's panel. Which importin-alpha reads that determinant has, as far as these queries reach, never been asked. A pan-fusion importin-alpha recovery is precisely what you would expect if one alpha isoform reads a determinant in the shared N-terminus, and it is also precisely what you would expect if importin-alpha is simply stuck to an overexpressed nuclear protein.
| uniprot | P52292 |
|---|---|
| length AA | 529 |
| accession resolution | Resolved live 2026-09-21: gene_exact:KPNA2 AND organism_id:9606 AND reviewed:true returns exactly ONE reviewed row, gene_primary KPNA2, P52292, entry name IMA1_HUMAN, 529 aa, synonyms RCH1 SRP1, protein name 'Importin subunit alpha-1 (Karyopherin subunit alpha-2) (RAG cohort protein 1) (SRP1-alpha)'. Matches Skucha's table. NOMENCLATURE HAZARD, recorded here because it is a genuine trap and is not in data/symbol-collisions.json: the GENE is KPNA2 (karyopherin alpha 2) and the PROTEIN is importin subunit alpha-1. The numbers do not match, and the older literature also uses importin-alpha-2 for the same protein under a different numbering convention. A reader checking 'is this importin alpha 2?' gets a confident answer either way depending on which convention they hold. The discriminators are the accession P52292 and the length 529. 'SRP1' additionally collides with the signal recognition particle protein SRP9/SRP14 family naming and with yeast SRP1. |
| localization | Cytoplasm (ECO:0000269, three PubMed citations) and Nucleus (ECO:0000269, two citations); also endoplasmic reticulum membrane (uncoded) and Golgi apparatus membrane (ECO:0000269). UniProt P52292, fetched 2026-09-21. |
| subnuclear localization | NOT ESTABLISHED. No subnuclear compartment is recorded for KPNA2 in UniProt and this beat located none in the literature. Recorded as an absence, not inferred from NUP50. |
| localization shown for fusion | NO - nobody has imaged KPNA2 in any KMT2A-rearranged cell, and nobody has asked which importin-alpha reads the KMT2A nuclear-import determinant. |
| shown for fusion | Co-purification with all seven MLL fusions including MLL-AF4 in Jurkat (p = 0.0167); shRNA-screened against MLL-AF9 in MOLM-13, score unpublished. NO independent experiment ties KPNA2 to any KMT2A fusion. The single record where a karyopherin term and a KMT2A term co-occur is about KPNB1 and HMGB2 in AML. |
| selectivity | UNKNOWN - not named among the paper's controls and not known to be among the 40 re-screened. Must not reach a target list. |
| functional screen | FUNCTIONAL SCREEN. Supplementary Data 2 (file MOESM5) is the shRNA library for the negative-selection screen: 768 rows, 128 unique gene symbols, exactly six shRNAs per gene - counted by this beat on 2026-09-21. All 128 conserved interactors were screened in MLL-AF9-expressing MOLM-13 cells, and the paper says so in those words ('scoring of shRNA-induced effects upon knockdown of all 128 MLL-fusion interactors'). So this protein WAS functionally tested against an MLL fusion, which is more than a co-purification. But the per-gene result is published only as the heatmaps in Fig. 2c/2d, with no table of scores anywhere in the paper or its five supplementary files, so the outcome for this protein is not recoverable. Absence class for that number: measured-not-reported - an afternoon with the authors' source data would close it. |
| absence class | never-measured |
| absence class note | Which importin-alpha isoform imports KMT2A or a KMT2A fusion has never been measured by anyone, despite this graph carrying an entry on the KMT2A nuclear-import determinant. The MOLM-13 shRNA score is separately measured-not-reported. PRIDE checked: PXD009338 is the only relevant deposition. |
| graph context | KPNA2 appears in ZERO node files before this entry (id listing over 1,900 nodes, 2026-09-21). Directly relevant existing entries: localization-nuclear-import-determinant-maps-to-the-at-hook-region and gene-tpr; gene-nup50 is written today in the same tranche. |
skucha 2018
{
"bait": "MLL-AF4 (= KMT2A::AFF1)",
"p_value": 0.0167,
"spectral_counts": "5|2",
"n_fusions_of_seven": 7,
"negative_control_counts": "0|0",
"per_bait": {
"MLL-AF1p": "0.0078 (5|3)",
"MLL-AF4": "0.0167 (5|2)",
"MLL-AF9": "0.0095 (8|7)",
"MLL-CBP": "0.0012 (7|8)",
"MLL-EEN": "0.0137 (7|8)",
"MLL-ENL": "0.0056 (11|7)",
"MLL-GAS7": "0.0114 (8|7)"
},
"af4_spectral_rank_of_seven": 7,
"index_bait_note": "p = 0.0167. The shallowest row in the tranche: 7 total MLL-AF4 spectra and only 18 at the deepest bait.",
"source": "analyses/skucha-mll-fusion-interactome/results.json, re-derived from the cached MOESM4 xlsx 2026-09-21; run.py re-run, both controls PASS"
}transport machinery composition
{
"question": "Is this a nuclear-transport-machinery carry-over?",
"answer": "The composition says NO - one adaptor, no receptor, no Ran.",
"in_the_960": {
"KPNA2": 7,
"NUP50": 7,
"TPR": 7,
"NUP153": 4,
"RANBP9 (CTLH scaffold, not transport)": 3,
"RANBP1": 1,
"RANBP10 (CTLH scaffold)": 1
},
"absent_at_any_n": [
"KPNB1",
"RAN",
"RCC1",
"KPNA1",
"KPNA3",
"KPNA4",
"KPNA6",
"IPO7",
"TNPO1",
"RANBP2",
"NUTF2",
"XPO1"
],
"reading": "The classical import adaptor is present without importin-beta and without Ran. Bulk soluble transport machinery would bring importin-beta first. What is present instead is the alpha adaptor together with the two nuclear-basket nucleoporins it is documented to associate with. Measured by this beat from the xlsx, 2026-09-21.",
"the_competing_reading": "KPNA2, NUP50 and NUP153 bind one another (PMID 23007389), so one genuine contact would deliver all three. This may be ONE recovery counted three times."
}cell types and states
[ "Jurkat (human T-ALL) - AP-MS host, nuclear lysate", "MOLM-13 (human MLL-AF9 AML) - shRNA screen host, six shRNAs, score unpublished", "mouse importin alpha crystal structure; permeabilised-cell import assays", "no leukaemia cell outside the two screen hosts, and no B-lineage KMT2A::AFF1 cell" ]
bounded literature
{
"query": "(KPNA2[tiab] OR \"karyopherin alpha 2\"[tiab] OR \"importin alpha-1\"[tiab]) AND (KMT2A[tiab] OR MLL[tiab] OR \"MLL-AF4\"[tiab] OR \"MLL-AF9\"[tiab] OR \"t(4;11)\"[tiab])",
"querytranslation": "(\"KPNA2\"[Title/Abstract] OR \"karyopherin alpha 2\"[Title/Abstract] OR \"importin alpha-1\"[Title/Abstract]) AND (\"KMT2A\"[Title/Abstract] OR \"MLL\"[Title/Abstract] OR \"MLL-AF4\"[Title/Abstract] OR \"MLL-AF9\"[Title/Abstract] OR \"t 4 11\"[Title/Abstract])",
"count": 0,
"date": "2026-09-21",
"tool": "NCBI esearch db=pubmed",
"names_tried": [
"KPNA2",
"karyopherin alpha 2",
"importin alpha-1",
"RCH1 and SRP1 NOT searched - both are overloaded and would have inflated rather than bounded the count",
"importin / importins / karyopherin (family form, run separately)"
],
"positive_control": "MEN1[tiab] AND the identical five-term clause returns 85.",
"family_level_query": "(importin[tiab] OR importins[tiab] OR karyopherin[tiab]) AND the same KMT2A clause returns 1: PMID 40082556, 'Targeting KPNB1 suppresses AML cells by inhibiting HMGB2 nuclear import' - a different karyopherin, a different cargo, and not a KMT2A fusion. Title-checked. So the family-level count is 1 and the on-topic count is 0.",
"bound": "Titles and abstracts only; supporting figures not searched. Cytogenetic term quoted; querytranslation shows 't 4 11'[Title/Abstract] with no injected [UID] term."
}functionally screened in the source paper
{
"_added": "king, cycle 48, 2026-09-21, after Q86 flagged that cycle-47 entries understate the record. Verified by me directly from the supplementary file, not from the paper's prose.",
"screened": true,
"library_symbol": "KPNA2",
"shrnas_for_this_gene": 6,
"design": "Supplementary Table 6 / MOESM5 is 768 data rows, 128 unique gene symbols, EXACTLY 6 shRNAs each -- counted with openpyxl on 2026-09-21. Negative-selection RNAi screen in MLL-AF9-expressing MOLM-13.",
"what_this_DOES_establish": "Every one of the 128 conserved MLL-fusion interactors, this protein included, was functionally tested against an MLL fusion. An entry saying 'nothing in the paper validates this prey' is true of BINDING and understates the record.",
"what_this_does_NOT_establish": "A per-gene result. Scores are presented as heatmaps (Fig. 2c/2d) and no per-gene depletion value is tabulated, so for any individual gene the outcome is measured-not-reported. It is also MLL-AF9 MOLM-13, a myeloid line, not the index fusion and not B-lineage.",
"absence_class_for_the_per_gene_score": "measured-not-reported"
}- Classical nuclear import is required by every cell; targeting importin-alpha is a general cell-biological intervention with a long history of non-selective toxicity.
- If the fusion depends on KPNA2 for import, blocking import would trap it in the cytoplasm - but the cytoplasmic pool of an oncoprotein is not necessarily inert, and this graph already records cytoplasmic pools with their own biology for other fusions.
- The whole transport reading may be one sub-assembly counted four times. A programme built on 'the fusion engages the nuclear basket and its adaptor' could be built on a single sticky contact.
- Which importin-alpha isoform reads the KMT2A N-terminal nuclear-import determinant? That determinant is retained in every fusion in Skucha's panel, which would explain a pan-fusion importin-alpha row exactly, and the experiment is a standard binding panel across the six alpha isoforms.
- Is the KPNA2/NUP50/NUP153/TPR group one recovery or four? Sequential depletion, or re-searching PXD009338 for the rest of the basket below the rank cutoff, would separate them.
- Importin-alpha in the nucleus is in its low-affinity, autoinhibited form. Was the fusion purified with importin-alpha because it was being imported, or because importin-alpha is stuck to an overexpressed nuclear protein? A cytoplasmic-fraction purification would discriminate, and Skucha et al. used nuclear lysate only.
- Does menin inhibition change the fusion's nuclear import or its basket association? Nothing in this project has asked where the displaced fusion goes at the level of transport.
- E1moderate confidence 3 of 5: One strong study, or several smaller consistent ones.paper
KPNA2 co-purified with all seven Strep-HA-tagged MLL fusions expressed as single-copy transgenes in isogenic human Jurkat T-ALL cells; for MLL-AF4 (= KMT2A::AFF1) the combined p-value is 0.0167 with spectral counts 5|2 and a negative control of 0|0.
MLL-fusion-driven leukemia requires SETD2 to safeguard genomic integrity. · Skucha A, Ebner J, Schmoellerl J, Roth M, Eder T, Cesar-Razquin A, Stukalov A, Vittori S, Muhar M, Lu B, Aichinger M, Jude J, Mueller AC, Gyorffy B, Vakoc CR, Valent P, Bennett KL, Zuber J, Superti-Furga G, Grebien F · Nature Communications 2018What this evidence cannot show
SYSTEM: the AP-MS host is JURKAT, a human T-ALL line, while KMT2A::AFF1 disease is B-lineage infant leukaemia; a partner requiring a B-cell or infant proteome cannot appear here and a T-lineage partner can appear spuriously. The bait is a Strep-HA-tagged, SINGLE-COPY, doxycycline-induced transgene at an FRT/Flp cassette, not the endogenous fusion. Prey came from bulk nuclear lysate (buffer C420, 420 mM NaCl) after a single STREP-Tactin step, so co-purification is NOT evidence of a direct contact. INCLUSION RULE: the paper kept the top 300 interactions per bait by combined p-value rather than applying a p threshold (Methods, verbatim: "All the identified bait-prey pairs were ranked by the combined p-value. The 300 most significant interactions per bait were retained."). Measured by this beat from the cached MOESM4 xlsx on 2026-09-21: 545 of the 2,049 per-bait p-values in the table (26.6%) exceed 0.05; within the MLL-AF4 column alone it is 186 of 291 (63.9%), and that column's maximum p is 0.175. MEASURED BY THIS BEAT, 2026-09-21, from the cached MOESM4 xlsx: across all 42 pan-fusion proteins the MLL-AF4 column carries the LOWEST total spectral counts of the seven baits for 34 of 42, and is sixth or seventh for 40 of 42. That is a bait-level property (transgene expression, purification depth or the DDX5/DDX17 GLM normalisation), not a statement about any one prey, so a low MLL-AF4 count must not be read as a weaker association than the same protein's count under another bait. For KPNA2 the MLL-AF4 total (7 spectra over two replicates) is rank 7 of the seven baits, against a maximum of 18 under another bait. All seven per-bait values, p (replicate spectral counts): MLL-AF1p 0.0078 (5|3); MLL-AF4 0.0167 (5|2); MLL-AF9 0.0095 (8|7); MLL-CBP 0.0012 (7|8); MLL-EEN 0.0137 (7|8); MLL-ENL 0.0056 (11|7); MLL-GAS7 0.0114 (8|7). SPECIFIC TO THIS PROTEIN: the shallowest row in the tranche - 7 total MLL-AF4 spectra, 18 at the deepest bait - so every conclusion rests on few peptides. KPNA2 is also one of the most abundant soluble nuclear/cytoplasmic proteins in a proliferating cell and is a recognised frequent flyer in affinity-purification experiments, which the clean 0|0 control argues against but does not exclude. SELECTIVITY: the paper's named non-selectivity controls are RFC1, SF3A3 and CCT3 - knockdown inhibited MLL-wild-type K562 and HL-60 as much as MOLM-13 - against MEN1 as the selective positive. Only 40 of the 128 ('the 40 candidate genes with the highest confidence') entered that MLL-r versus MLL-wild-type re-screen, and the paper does not list which 40. This protein is not named among the controls, but that is NOT evidence of selectivity: it is equally consistent with the protein never having reached the second screen. Recorded as unknown, and this entry must not be read as nominating a target. Values re-read from the cached xlsx on 2026-09-21 and cross-checked against analyses/skucha-mll-fusion-interactome/results.json, whose two controls (128 proteins shared by >=5 baits and 42 by all seven, both matching the paper; MEN1 present with all seven) both PASS on today's re-run.
Evidence that argues against this (2)
- IntAct has never curated this dataset, so no independent curator has re-examined these calls and no interactome-coverage metric built on IntAct can see them; the raw spectra at ProteomeXchange PXD009338 have not been reanalysed here. The authors themselves removed seven proteins from the shared set by hand as 'either frequently observed contaminants or ... not detected in human hematopoietic cell lines', which concedes that the rank cutoff lets contaminants through - and ACTB survived that filter, sitting in the pan-fusion 42 with a NON-ZERO negative control (3|3). Ten of the 42 carry a non-zero negative control: PSIP1 0|5, MCM2 0|2, ACTB 3|3, CSNK2A1 2|0, RUNX1 0|2, SF3A3 0|3, TCEB3 0|1, CHD4 2|2, SMARCC1 1|0, ZNF512 0|2 - counted by this beat from the xlsx neg_ctrl column, 2026-09-21. ProteomeXchange/PRIDE 2018
- The paper states that 'more than one third of proteins in the network of conserved MLL-fusion protein interaction partners were identified as essential in recent genome-wide screens'. Abundance and essentiality both raise the odds of recovery in an AP-MS experiment, so membership in the conserved core is partly a statement about how much of a protein is present in a nucleus, not only about what it binds. Skucha A et al. 2018
- E2established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.paper
The 2.5 A crystal structure of mammalian importin alpha shows a large C-terminal armadillo-repeat domain and a less structured N-terminal importin-beta-binding domain containing an internal nuclear localization signal bound to the NLS-binding site, explaining the regulatory switch between the cytoplasmic high-affinity and nuclear low-affinity forms, with importin beta converting the low- to the high-affinity form by binding a site overlapping the autoinhibitory sequence.
Autoinhibition by an internal nuclear localization signal revealed by the crystal structure of mammalian importin alpha. · Kobe B · Nat Struct Biol 1999What this evidence cannot show
1999, Nature Structural Biology; a MOUSE importin alpha crystal structure at 2.5 A. The human orthologue KPNA2 is the protein in this entry and the structure is of the mouse protein, so residue-level statements should not be carried across without alignment - none are made here. Not haematopoietic, not a fusion system. Read from the abstract. This project's standing PDB rules apply: no residue span is asserted in this entry and none should be read off the deposit.
Evidence that argues against this (1)
- The autoinhibition model predicts that importin-alpha in the nucleus is in its LOW-affinity form for NLS cargo. A purification from nuclear lysate therefore recovers importin-alpha in the state least likely to be gripping a cargo, which is an argument that the KPNA2 row is not a cargo-receptor interaction with the fusion. Friedrich B et al. 2006
- E3strong confidence 4 of 5: Replicated in peer-reviewed work by more than one group.paper
Both the nuclear localization signal sequence and the surrounding protein context contribute to which importin alpha isoform transports a cargo: swapping the NLSs of RCC1, preferentially imported by importin alpha3, and of the less specifically imported nucleoplasmin did not transfer isoform specificity in binding studies or nuclear import assays.
Nuclear localization signal and protein context both mediate importin alpha specificity of nuclear import substrates. · Friedrich B, Quensel C, Sommer T, Hartmann E, Kohler M · Mol Cell Biol 2006What this evidence cannot show
2006, Molecular and Cellular Biology; in vitro binding and permeabilised-cell import assays with two model cargoes. Not haematopoietic, not a fusion system, and generalising from two cargoes to a rule about isoform specificity is the paper's own framing rather than a proven law. Read from the abstract. Cited here for one purpose: to establish that recovering ONE alpha isoform out of six is a potentially informative observation rather than a generic transport signal.
Evidence that argues against this (1)
- KPNA2 is the most abundant alpha importin in proliferating cells and is broadly overexpressed in cancer, so recovering it rather than another isoform may reflect its abundance in the Jurkat proteome and not cargo specificity. No abundance-normalised comparison exists for this dataset. Skucha A et al. 2018
- E4strong confidence 4 of 5: Replicated in peer-reviewed work by more than one group.paper
Nup153 provides the scaffold for Nup50 through a dual interface, one site in Nup153's unique N-terminal region critical for Nup50's pore localisation and a second at Nup153's distal tail that is importin-alpha-dependent, so that the Nup153 scaffold provides a local environment bringing Nup50 and importin alpha together.
The Nup153-Nup50 protein interface and its role in nuclear import. · Makise M, Mackay DR, Elgort S, Shankaran SS, Adam SA, Ullman KS · J Biol Chem 2012What this evidence cannot show
2012, J Biol Chem; domain mapping and import assays in cultured human cells. Not haematopoietic, not a fusion system. Read from the abstract. Cited here because NUP50, NUP153 and KPNA2 are all in the Skucha network, which makes their joint recovery a documented sub-assembly rather than three independent facts.
Evidence that argues against this (1)
- This is the strongest argument AGAINST treating KPNA2, NUP50 and NUP153 as three separate pieces of evidence about the fusion. Proteins that bind each other co-purify as a unit; one genuine contact anywhere in that group would deliver all of them. The interactome cannot say which, if any, is the anchor. Skucha A et al. 2018
co-purified, all 7 MLL fusions, Jurkat AP-MS, MLL-AF4 p=0.0167 (5|2)
importin-alpha binds NUP50 and the NUP153 distal tail; all three are in this network
the KMT2A import determinant is retained in all seven baits; which importin-alpha reads it has never been asked
- co-occurs with →TPR / Megator (P12270) - the nuclear-basket nucleoporin that builds heterochromatin exclusion zones, in the pan-MLL-fusion core
KPNA2, NUP50, TPR and NUP153 are the only transport-related proteins in the 960; no importin-beta, no Ran