caseStudyTwo.RmdCorces et al measured RNA-seq and ATAC-seq in thirteen distinct human primary hematopoiesis cell types. Here we explore whether these data, in contrast to bulk GTEx blood RNA-seq, allow us to predict the regulation of NFE2. We use the same progressive approach for the selection of candidate transcription factors: all annotated TFs, all TFs with motifs, TFs with stringent or relaxed binding and sequence conservation scores.
The GeneOntology project annotates 1663 human genes to the molecular function DNA-binding transcription factor activity:
> tfs.all length(tfs.all) # 1663
> target.gene tfs length(tfs) # 1534
> solver tbl dim(tbl) # 1530 8
> new.order tbl rownames(tbl) tbl.goAll head(tbl.goAll, n=20)
gene betaLasso lassoPValue pearsonCoeff rfScore betaRidge spearmanCoeff xgboost
1 LMO2 0.047541125 5.249385e-20 0.8101163 8.702037e+00 0.007119946 0.6555403 1.500191e-01
2 NFIX 0.093098353 5.384999e-20 0.8099891 6.852083e+00 0.008154300 0.7870852 5.241650e-02
3 ZNF80 -0.066366470 6.490916e-20 -0.8096562 1.052108e+01 -0.008193182 -0.7093304 5.867285e-01
4 GFI1B 0.226649379 2.578638e-19 0.8016940 2.483361e+00 0.009161609 0.7929971 4.310633e-08
5 MITF 0.177632172 5.326661e-19 0.8009208 6.091928e+00 0.008086801 0.6164877 6.660835e-05
6 MAFG 0.057656557 1.079359e-16 0.7905432 3.829226e+00 0.007892880 0.7665661 1.711896e-04
7 GATA2 0.000000000 2.166205e-03 0.7691669 1.720552e+00 0.007813329 0.6851964 9.772821e-07
8 IKZF3 0.000000000 1.000000e+00 -0.7620993 4.786622e+00 -0.006253381 -0.3980242 1.528179e-06
9 LYL1 0.006733866 1.179134e-08 0.7581465 1.184926e+00 0.006740238 0.7822108 0.000000e+00
10 HOXA5 0.000000000 1.000000e+00 0.7312527 1.621898e+00 0.005573155 0.4879902 1.384144e-07
11 HOXA10 0.000000000 1.000000e+00 0.7262372 2.515769e-01 0.004681578 0.5537364 0.000000e+00
12 SP140 0.000000000 1.000000e+00 -0.7127619 1.478112e+00 -0.006094842 -0.5231002 0.000000e+00
13 ETS1 -0.020158108 4.193672e-11 -0.7070259 4.233599e+00 -0.007438296 -0.5267590 0.000000e+00
14 NR6A1 0.000000000 1.000000e+00 0.6971826 6.104783e-02 0.004443842 0.5772753 0.000000e+00
15 BCL11B 0.000000000 1.000000e+00 -0.6951305 6.063338e-05 -0.005375201 -0.4351164 0.000000e+00
16 IRF4 -0.012852384 2.796501e-10 -0.6919585 6.507420e-02 -0.007734237 -0.5694599 0.000000e+00
17 CEBPA 0.012159852 2.784620e-10 0.6864443 4.485537e-01 0.007222885 0.5459188 7.626946e-04
18 MEIS1 0.000000000 1.000000e+00 0.6815312 1.375627e-01 0.003999963 0.5606262 0.000000e+00
19 CBFA2T3 0.000000000 1.000000e+00 0.6809550 3.927459e-03 0.005125665 0.5737458 4.681401e-06
20 SMAD1 0.000000000 4.842264e-02 0.6758645 1.686901e+00 0.006522420 0.5366757 0.000000e+00
> match(c("GATA1", "TAL1", "KLF1"), tbl.goAll$gene)
[1] 116 38 51
The JASPAR 2018 and Hocomoco transcription factor compendia, when combined, identify 780 annotated transcription factor motif. In building the next model, candidate transcription factors are limited to this set.
> tfs.with.motifs length(tfs.with.motifs)
[1] 780
> tfs length(tfs)
[1] 509
>
> solver suppressWarnings(
> tbl )
> dim(tbl) # 507 8
> new.order tbl rownames(tbl) tbl.withMotifs head(tbl.withMotifs, n=20
gene betaLasso lassoPValue pearsonCoeff rfScore betaRidge spearmanCoeff xgboost
1 NFIX 0.10626036 5.375931e-20 0.8099891 10.93109147 0.020402127 0.7870852 5.449019e-01
2 GFI1B 0.25679512 3.100623e-19 0.8016940 6.88338652 0.022793570 0.7929971 2.273725e-02
3 MITF 0.20075697 2.815766e-19 0.8009208 7.83112670 0.016352198 0.6164877 1.779597e-01
4 MAFG 0.06992969 2.477448e-17 0.7905432 5.69753582 0.017553696 0.7665661 3.340823e-05
5 GATA2 0.00687861 6.610933e-02 0.7691669 1.99289713 0.016963665 0.6851964 5.200143e-05
6 HOXA5 0.00000000 1.000000e+00 0.7312527 3.05457854 0.013316331 0.4879902 0.000000e+00
7 HOXA10 0.00000000 1.420628e-01 0.7262372 0.75941803 0.014015820 0.5537364 6.400621e-06
8 ETS1 -0.06970416 3.556011e-13 -0.7070259 8.07010777 -0.018193677 -0.5267590 0.000000e+00
9 NR6A1 0.00000000 2.461098e-01 0.6971826 0.41803310 0.011750808 0.5772753 0.000000e+00
10 IRF4 -0.02169888 1.360509e-10 -0.6919585 0.46599226 -0.020261614 -0.5694599 0.000000e+00
11 CEBPA 0.03482203 9.188178e-11 0.6864443 0.69499215 0.014358728 0.5459188 1.349195e-04
12 MEIS1 0.00000000 1.000000e+00 0.6815312 0.33666404 0.012905598 0.5606262 0.000000e+00
13 SMAD1 0.00000000 4.204800e-02 0.6758645 3.70105486 0.016631861 0.5366757 1.032892e-08
14 TFEC 0.00000000 1.000000e+00 0.6740365 1.17192544 0.013276577 0.4392922 1.344201e-01
15 RFX2 0.00000000 1.000000e+00 0.6670588 0.03802791 0.011815788 0.6588538 1.071266e-06
16 MYBL1 0.00000000 1.000000e+00 -0.6585463 1.31516074 -0.014894704 -0.4524598 0.000000e+00
17 MYCN 0.00000000 1.000000e+00 0.6554632 0.09194602 0.014752993 0.5671422 2.840913e-06
18 TBX21 0.00000000 1.000000e+00 -0.6442284 0.28941161 -0.013417225 -0.4703482 4.371519e-08
19 FOSB 0.00000000 1.000000e+00 0.6433983 0.36776177 0.011620625 0.4334291 0.000000e+00
20 ERG 0.00000000 1.000000e+00 0.6353066 0.14183513 0.009995614 0.4743840 2.279443e-07
> match(c("GATA1", "TAL1", "KLF1"), tbl.withMotifs$gene)
[1] 58 21 28
We hypothesize that transcription factors binding sites with well-matched motifs found in highly conserved regulatory regions within +/- 10kb of the target gene’s TSS are likely to be functional. When found, and when tf/target gene expression is also correlated, or anti-correlated, these are possibly useful trena predictions, worthy of further consideration.
Here we use a precalculated table of FIMO and phast7 scores for 20kb surrounding the NFE2 transcription start site, extracting only those TFs with very high match and conservation. With these data and assumptions, GATA1 rises to rank 8 in the model with a pearson correlation of 0.5. consisent with expectation and the findings of the published papers.
phast.score = phast.score) dim(tbl.fimo.strong) tfs All three transcription factors are now found among the top regulators in the model:> match(c("GATA1", "TAL1", "KLF1"), tbl.corces.fimo$gene) # 8 4 5 [1] 8 4 5Cusanovich 2014 establised that function transcription factors tend to have
Our heuristic has been to select for only very high conservation and sequence match, but it is widely recognized that TF binding is more promiscuous than that. So now we add two columns to the model table showing binding site counts for strict and lenient motif/conservation scoring. Extra credence is conferred on TFs which rank high in the model and which, by one or both measures, has multiple binding sites.
tfbs.strong counts are of sites with phast7 conservation score (opossum - primates) > 0.90 and FIMO motif match < 1e-5.
tfbs.weak counts with phast7 > 0.5 and FIMO < 1e-4.
gene betaLasso lassoPValue pearsonCoeff rfScore betaRidge spearmanCoeff xgboost tfbs.strong tfbs.weak
1 NR6A1 0.114 4.83e-13 0.697 9.074 0.087 0.577 0.011 1 3
2 IRF4 -0.203 7.95e-13 -0.692 9.941 -0.119 -0.569 0.026 1 9
3 CEBPA 0.246 2.82e-12 0.686 14.259 0.091 0.546 0.575 1 9
4 TAL1 0.035 1.39e-08 0.630 6.931 0.099 0.648 0.028 1 2
5 KLF1 0.211 1.84e-10 0.610 6.682 0.100 0.740 0.054 4 28
6 EGR1 0.032 2.76e-06 0.568 4.730 0.072 0.449 0.003 2 11
7 KLF4 0.032 1.35e-05 0.556 6.292 0.068 0.348 0.000 2 4
8 GATA1 0.000 8.36e-01 0.500 1.287 0.071 0.597 0.269 1 4
9 SPI1 0.000 3.86e-03 0.497 1.454 0.057 0.443 0.000 2 9
10 WT1 0.000 3.67e-03 0.462 0.772 0.066 0.400 0.003 2 4
11 MAZ 0.000 8.52e-01 0.434 1.133 0.038 0.523 0.003 1 6
12 KLF16 0.000 7.26e-01 0.363 0.904 0.018 0.470 0.001 2 7
13 NFIC 0.000 6.98e-01 0.359 0.785 0.023 0.439 0.000 4 36
14 SP4 0.000 6.70e-01 -0.352 0.933 -0.040 -0.203 0.000 1 3
15 RARA 0.000 6.91e-01 0.279 0.434 0.013 0.305 0.000 3 12
16 KLF8 0.000 3.74e-02 -0.270 1.202 -0.058 -0.153 0.000 1 10
17 SP1 0.000 3.06e-01 0.261 0.355 0.039 0.322 0.000 1 3
18 MNT 0.000 4.52e-01 0.234 0.543 0.001 0.368 0.007 1 3
19 TFCP2 0.000 9.85e-01 0.228 0.858 0.026 0.267 0.002 1 6
20 STAT3 0.000 9.73e-01 0.222 1.293 0.012 0.405 0.003 4 30