tooluniverse-regulatory-genomics

Regulatory Genomics Research Skill

Systematic investigation of gene regulation through transcription factor binding, chromatin state, and regulatory element annotation. Integrates JASPAR (TF motifs), ENCODE (functional genomics experiments), RegulomeDB (regulatory variant scoring), and UCSC cCREs.

Domain Reasoning

Regulatory element identification requires converging lines of evidence: sequence conservation alone is insufficient (many conserved sequences are not regulatory), chromatin accessibility is necessary but not sufficient (open chromatin can be structural), TF binding peaks require motif validation, and eQTL evidence ties the element to a transcriptional outcome. No single data type is sufficient. A high-confidence regulatory element requires at least two independent evidence types, and ideally all four.

LOOK UP DON'T GUESS

• TF binding motifs: retrieve from jaspar_search_matrices and jaspar_get_matrix; do not describe motifs from memory.
• Experimental ChIP-seq data: search ENCODE_search_experiments; do not assume a TF has been profiled in a given cell type.
• cCRE annotations for a genomic region: call UCSC_get_encode_cCREs with exact coordinates; do not guess element types.
• Regulatory impact of a variant: query RegulomeDB_query_variant; never estimate regulatory importance from position alone.

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KEY PRINCIPLES:

1. English-first queries - Use English gene/TF names in all tool calls; respond in user's language
2. Evidence layering - Combine motif (JASPAR) + experimental (ENCODE ChIP-seq) + variant (RegulomeDB) evidence
3. Coordinate precision - Genome coordinates must specify assembly (GRCh38 preferred)
4. Negative results documented - Report when a TF has no ChIP-seq data in ENCODE

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COMPUTE, DON'T DESCRIBE

When analysis requires computation (statistics, data processing, scoring, enrichment), write and run Python code via Bash. Don't describe what you would do — execute it and report actual results. Use ToolUniverse tools to retrieve data, then Python (pandas, scipy, statsmodels, matplotlib) to analyze it.

When to Use

• "What transcription factors bind near gene X?"
• "Does this SNP affect a regulatory element?"
• "Find CTCF binding sites in liver tissue"
• "What are the enhancers active in this cell type?"
• "Show me ChIP-seq experiments for H3K27ac in T cells"
• "Is rs1234567 in a regulatory region?"
• "What TF motifs overlap this genomic region?"
• "Find ENCODE experiments for ATAC-seq in cancer cell lines"

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Key Tools

Tool	Purpose	Key Params
jaspar_search_matrices	Find TF binding motifs by TF name or organism	name, species, collection, tax_id
jaspar_get_matrix	Get full PWM/PFM for a specific JASPAR matrix	matrix_id (e.g., "MA0139.1")
JASPAR_get_transcription_factors	List all TF matrices (paginated)	page, page_size
ENCODE_search_experiments	Search ENCODE ChIP-seq/ATAC-seq/WGBS experiments	assay_title, target, biosample_term_name, limit
ENCODE_search_histone_experiments	Search histone mark ChIP-seq specifically	histone_mark, biosample_term_name, limit
ENCODE_search_chromatin_accessibility	Search ATAC-seq/DNase-seq experiments	biosample_term_name, limit
ENCODE_get_experiment	Get full metadata for a specific ENCODE experiment	accession (e.g., "ENCSR000EGM")
ENCODE_search_annotations	Search ENCODE cCRE and chromatin state annotations	annotation_type, biosample_term_name, limit
ENCODE_get_chromatin_state	Search ChromHMM segmentation data	biosample_term_name, limit
UCSC_get_encode_cCREs	Get cCREs overlapping a genomic region	chrom, start, end
RegulomeDB_query_variant	Score regulatory impact of a variant	rsid (e.g., "rs4994")
ENCODE_search_biosamples	Find available cell lines/tissues in ENCODE	term_name, biosample_type, limit

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Workflow

Phase 1: TF Motif Discovery (JASPAR)

When asked about TF binding motifs or what TFs might regulate a gene:

1. jaspar_search_matrices(name="TF_NAME", species="Homo sapiens")
   -> Returns list of matrices with matrix_id, collection, version

2. jaspar_get_matrix(matrix_id="MA0139.1")
   -> Returns full PFM/PWM matrix, sequence logo URL, binding sites URL

3. For broad TF family search:
   jaspar_search_matrices(species="Homo sapiens", collection="CORE")
   -> Filter by TF family name in results

JASPAR Collections:

• CORE: High-quality, non-redundant matrices (best for most use cases)
• CNE: Conserved non-coding elements
• POLII: RNA Pol II binding sites

Key Response Fields:

• matrix_id: Versioned ID (e.g., "MA0139.1") — use for jaspar_get_matrix
• name: TF gene symbol
• sequence_logo: URL to binding site logo PNG/SVG
• collection: Which JASPAR collection

Phase 2: ENCODE Experiment Search

When looking for ChIP-seq, ATAC-seq, or other functional genomics data:

For TF ChIP-seq:

ENCODE_search_experiments(
    assay_title="TF ChIP-seq",
    target="CTCF",              # TF gene name
    biosample_term_name="HepG2", # Cell line or tissue
    limit=10
)

For histone marks:

ENCODE_search_histone_experiments(
    histone_mark="H3K27ac",         # or H3K4me3, H3K27me3, H3K36me3
    biosample_term_name="liver",
    limit=10
)

For chromatin accessibility:

ENCODE_search_chromatin_accessibility(
    biosample_term_name="T cell",
    limit=10
)

For regulatory annotations (cCREs, ChromHMM):

ENCODE_search_annotations(
    annotation_type="candidate Cis-Regulatory Elements",
    biosample_term_name="K562",
    limit=10
)

Common assay_title values:

• "TF ChIP-seq" - Transcription factor binding
• "Histone ChIP-seq" - Histone modification
• "ATAC-seq" - Chromatin accessibility
• "DNase-seq" - Open chromatin (older method)
• "WGBS" - DNA methylation

Note: ENCODE_search_experiments returns experiment metadata only (accession, biosample, status). Use ENCODE_get_experiment(accession) to get file download links and detailed metadata.

Phase 3: cCRE Annotation (UCSC + ENCODE)

When annotating a specific genomic region:

UCSC_get_encode_cCREs(
    chrom="chr8",       # Chromosome (GRCh38)
    start=37966000,     # Start coordinate
    end=37967000        # End coordinate
)
# Returns cCREs with type: pELS (proximal enhancer), dELS (distal enhancer),
# PLS (promoter-like), CTCF-only, DNase-H3K4me3

cCRE Types:

• PLS (Promoter-like): High DNase + H3K4me3 + H3K27ac signal near TSS
• pELS (Proximal Enhancer): High DNase + H3K27ac, within 2kb of TSS
• dELS (Distal Enhancer): High DNase + H3K27ac, >2kb from TSS
• CTCF-only: CTCF binding without enhancer marks
• DNase-H3K4me3: Unclassified accessible region

Phase 4: Regulatory Variant Scoring (RegulomeDB)

When assessing regulatory impact of a variant:

RegulomeDB_query_variant(rsid="rs4994")
# Returns:
#   regulome_score.ranking: "1a"-"7" (1a = highest regulatory evidence)
#   regulome_score.probability: 0-1 continuous score
#   tissue_specific_scores: dict of tissue -> score
#   overlapping features: eQTLs, TF binding, DNase peaks, motifs

RegulomeDB Score Interpretation:

Rank	Meaning
1a	eQTL + TF binding + matched TF motif + DNase peak
1b	eQTL + TF binding + DNase peak
1c	eQTL + TF binding or DNase peak
1d	eQTL + motif or protein binding
1e	eQTL + motif hit
1f	eQTL only
2a	TF binding + motif match + DNase
2b	TF binding + matched motif
2c	TF binding with/without motif
3a	DNase peak + motif
3b	DNase peak only
4	Motif hit only
5	Proximity to Footprint
6	Proximity to Footprint + TF
7	No evidence

Variants with rank 1a-2b are most likely to affect gene regulation.

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Tool Parameter Reference

Tool	Required Params	Optional Params	Notes
jaspar_search_matrices	(none — returns all if empty)	name, species, collection, tax_id, page, page_size	Use name for TF name search
jaspar_get_matrix	matrix_id	—	Full version required: "MA0139.1" not "MA0139"
JASPAR_get_transcription_factors	(none)	page, page_size	Paginated; default page_size=10
jaspar_get_matrix_versions	base_id	—	base_id is unversioned (e.g., "MA0139")
ENCODE_search_experiments	(none — returns all if empty)	assay_title, target, biosample_term_name, limit	assay_title must match ENCODE vocabulary exactly
ENCODE_search_histone_experiments	(none)	histone_mark, biosample_term_name, limit	histone_mark: "H3K27ac", "H3K4me3", etc.
ENCODE_search_chromatin_accessibility	(none)	biosample_term_name, limit	Returns ATAC-seq and DNase-seq
ENCODE_get_experiment	accession	—	accession: "ENCSR..." format
ENCODE_search_annotations	(none)	annotation_type, biosample_term_name, limit	annotation_type: "candidate Cis-Regulatory Elements"
ENCODE_get_chromatin_state	(none)	biosample_term_name, limit	Returns ChromHMM segmentation
ENCODE_search_biosamples	(none)	term_name, biosample_type, limit	biosample_type: "cell line", "tissue", "primary cell"
UCSC_get_encode_cCREs	chrom, start, end	—	Coordinates in GRCh38; chrom format: "chr1"
RegulomeDB_query_variant	rsid	—	rsid format: "rs4994" (with rs prefix)

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Common Patterns

Pattern 1: TF Binding Site Investigation

Goal: Find where TF X binds and what motif it recognizes
Flow:
  1. jaspar_search_matrices(name="CTCF") -> get matrix_id
  2. jaspar_get_matrix(matrix_id) -> get full PWM, logo URL
  3. ENCODE_search_experiments(assay_title="TF ChIP-seq", target="CTCF") -> experimental binding data
  4. For specific tissue: add biosample_term_name="HepG2"
Output: Motif logo + experimental binding evidence

Pattern 2: Regulatory Variant Interpretation

Goal: Assess if variant rs1234567 affects gene regulation
Flow:
  1. RegulomeDB_query_variant(rsid="rs1234567") -> score + overlapping features
  2. If score <= 2b: ENCODE_search_experiments(target=overlapping_TF) -> experimental evidence
  3. UCSC_get_encode_cCREs(chrom, start, end) -> check if variant in known cCRE
Output: Regulatory score + supporting evidence + cCRE context

Pattern 3: Cell-Type Regulatory Landscape

Goal: Characterize active enhancers in a cell type
Flow:
  1. ENCODE_search_histone_experiments(histone_mark="H3K27ac", biosample_term_name="K562") -> active enhancers
  2. ENCODE_search_chromatin_accessibility(biosample_term_name="K562") -> open chromatin
  3. ENCODE_search_annotations(annotation_type="candidate Cis-Regulatory Elements", biosample_term_name="K562")
  4. ENCODE_get_chromatin_state(biosample_term_name="K562") -> ChromHMM states
Output: Active regulatory elements specific to the cell type

Pattern 4: Gene Regulatory Region Mapping

Goal: Find all regulatory elements near a gene
Flow:
  1. Get gene coordinates from MyGene_query_genes or ensembl_lookup_gene
  2. UCSC_get_encode_cCREs(chrom, start-50000, end+50000) -> nearby cCREs
  3. ENCODE_search_experiments(target=TF_OF_INTEREST) -> TF binding data
  4. jaspar_search_matrices(name=TF_NAME) -> motif for TF
Output: Map of regulatory elements around gene with evidence types

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Fallback Strategies

Primary Tool	Fallback	When
ENCODE_search_experiments with specific biosample	Remove biosample_term_name filter	No results for specific tissue
jaspar_search_matrices(name=TF)	jaspar_search_matrices(name=TF_family)	TF not found by exact name
UCSC_get_encode_cCREs	ENCODE_search_annotations without coordinates	If coordinates unknown
RegulomeDB_query_variant(rsid)	Use ENCODE_search_experiments + JASPAR to manually assess overlap	rsid not in RegulomeDB

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Limitations

• ENCODE TF ChIP-seq: assay_title="TF ChIP-seq" uses ENCODE's exact controlled vocabulary — avoid "ChIP-seq" (too general)
• UCSC cCREs: Coordinates must be in GRCh38 (hg38); liftOver required for hg19 variants
• RegulomeDB: Only scores variants with known rsIDs; novel variants not supported
• JASPAR: Provides motif databases only — not genomic binding locations; combine with ENCODE for experimental evidence
• ENCODE experiment results: The @graph field may be empty if query filters are too restrictive; relax filters and retry