FB2024_02 , released April 23, 2024
Gene: Dmel\Lkb1
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General Information
Symbol
Dmel\Lkb1
Species
D. melanogaster
Name
Lkb1 kinase
Annotation Symbol
CG9374
Feature Type
FlyBase ID
FBgn0038167
Gene Model Status
Stock Availability
Enzyme Name (EC)
non-specific serine/threonine protein kinase (2.7.11.1)
Gene Summary
Lkb1 kinase (Lkb1) encodes a serine/threonine kinase that plays a master role for activating the AMP-dependent protein kinase (AMPK) family kinases. It is a well-characterized tumor suppressor and regulates processes like cell polarity, metabolism, apoptosis, and cell growth. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
Also Known As

PAR-4, dlkb1, Par4, STK11

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
3-54
RefSeq locus
NT_033777 REGION:13676549..13679430
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (28 terms)
Molecular Function (5 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
enables ATP binding
inferred from electronic annotation with InterPro:IPR000719, InterPro:IPR017441
inferred from sequence or structural similarity with HGNC:11389
inferred from electronic annotation with InterPro:IPR039154
inferred from biological aspect of ancestor with PANTHER:PTN002519176
Biological Process (18 terms)
Terms Based on Experimental Evidence (14 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from mutant phenotype
inferred from direct assay
involved_in dorsal closure
inferred from mutant phenotype
inferred from direct assay
inferred from mutant phenotype
inferred from direct assay
inferred from mutant phenotype
inferred from mutant phenotype
inferred from direct assay
inferred from mutant phenotype
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
inferred from electronic annotation with InterPro:IPR039154
inferred from electronic annotation with InterPro:IPR039154
inferred from biological aspect of ancestor with PANTHER:PTN002519176
inferred from electronic annotation with InterPro:IPR039154
Cellular Component (5 terms)
Terms Based on Experimental Evidence (5 terms)
CV Term
Evidence
References
located_in cell cortex
inferred from direct assay
inferred from direct assay
located_in cytoplasm
inferred from direct assay
located_in endosome
inferred from direct assay
located_in nucleus
inferred from direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
is_active_in cytoplasm
inferred from biological aspect of ancestor with PANTHER:PTN002519176
Protein Family (UniProt)
-
Catalytic Activity (EC/Rhea)
protein serine/threonine kinase activity
(1) ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] (2.7.11.1)
(2) ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl- [protein] (2.7.11.1)
Summaries
Gene Snapshot
Lkb1 kinase (Lkb1) encodes a serine/threonine kinase that plays a master role for activating the AMP-dependent protein kinase (AMPK) family kinases. It is a well-characterized tumor suppressor and regulates processes like cell polarity, metabolism, apoptosis, and cell growth. [Date last reviewed: 2019-03-14]
Gene Group (FlyBase)
CALCIUM/CALMODULIN-DEPENDENT PROTEIN KINASES -
The Calcium/Calmodulin-dependent kinase family are serine/threonine kinases which, in general, prefer substrates containing basic residues. Many, but not all, members are regulated by calcium or calmodulin. (Adapted from FBrf0132098).
LKB1-STRAD-MO25 SERINE/THREONINE PROTEIN KINASE COMPLEX -
The LKB1-STRAD-MO25 complex is a heterotrimeric serine/threonine protein kinase complex of Lkb1 and two regulatory subunits, that are required for the activity of the kinase. (Adapted from PMID:19892943.)
Summary (Interactive Fly)

Par-4 kinase - required for the early A-P polarity of the oocyte and for the repolarization of the oocyte cytoskeleton that defines the embryonic A-P axis

Gene Model and Products
Number of Transcripts
9
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\Lkb1 for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)
Isoform displayed:
Pfam protein domains
InterPro name
classification
start
end
Protein Domains (via SMART)
Isoform displayed:
SMART protein domains
InterPro name
classification
start
end
Structure
Protein 3D structure   (Predicted by AlphaFold)   (AlphaFold entry Q8T9L5)

If you don't see a structure in the viewer, refresh your browser.
Model Confidence:
  • Very high (pLDDT > 90)
  • Confident (90 > pLDDT > 70)
  • Low (70 > pLDDT > 50)
  • Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures
Crossreferences
Comments on Gene Model

Annotated transcripts do not represent all possible combinations of alternative exons and/or alternative promoters.

Gene model reviewed during 5.47

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0082808
2428
567
FBtr0082809
2397
567
FBtr0082810
2391
567
FBtr0082811
2422
567
FBtr0082812
2553
567
FBtr0082813
2407
567
FBtr0082814
2401
567
FBtr0082815
2403
567
FBtr0301488
2487
567
Additional Transcript Data and Comments
Reported size (kB)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0082276
62.9
567
5.58
FBpp0082277
62.9
567
5.58
FBpp0082278
62.9
567
5.58
FBpp0082279
62.9
567
5.58
FBpp0082280
62.9
567
5.58
FBpp0082281
62.9
567
5.58
FBpp0082282
62.9
567
5.58
FBpp0082283
62.9
567
5.58
FBpp0290703
62.9
567
5.58
Polypeptides with Identical Sequences

The group(s) of polypeptides indicated below share identical sequence to each other.

Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Lkb1 using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Expression Data
Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

4.64

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
organism

Comment: maternally deposited

Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in cell cortex
inferred from direct assay
inferred from direct assay
located_in cytoplasm
inferred from direct assay
located_in endosome
inferred from direct assay
located_in nucleus
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Lkb1 in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Reference
See Gelbart and Emmert, 2013 for analysis details and data files for all genes.
Developmental Proteome: Life Cycle
Developmental Proteome: Embryogenesis
External Data and Images
Linkouts
BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 16 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 37 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Lkb1
Transgenic constructs containing regulatory region of Lkb1
Aberrations (Deficiencies and Duplications) ( 3 )
Inferred from experimentation ( 3 )
Inferred from location ( 0 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Sterility
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
centrosome & larval neuroblast (with Df(3R)urd)
oocyte & microtubule | germ-line clone
spindle & larval neuroblast (with Df(3R)urd)
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (14)
11 of 14
Yes
Yes
2  
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
1  
1 of 14
No
No
4  
1 of 14
No
No
2  
1 of 14
No
No
Hsap\SIK1B
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (13)
11 of 14
Yes
Yes
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (14)
11 of 14
Yes
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (8)
8 of 13
Yes
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Danio rerio (Zebrafish) (17)
11 of 14
Yes
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (7)
9 of 14
Yes
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
Yes
1 of 14
No
No
Anopheles gambiae (African malaria mosquito) (6)
10 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (30)
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
Yes
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
Saccharomyces cerevisiae (Brewer's yeast) (4)
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
1 of 13
Yes
No
Schizosaccharomyces pombe (Fission yeast) (2)
2 of 12
Yes
No
1 of 12
No
No
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Lkb1. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (10)
3 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
Human Disease Associations
FlyBase Human Disease Model Reports
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 5 )
Potential Models Based on Orthology ( 3 )
Modifiers Based on Experimental Evidence ( 3 )
Disease Associations of Human Orthologs (via DIOPT v9.1 and OMIM)
Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
Functional Complementation Data
Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.
Interactions
Summary of Physical Interactions
esyN Network Diagram
Show neighbor-neighbor interactions:
Show/hide secondary interactors 
(data from AllianceMine provided by esyN)
Select Layout:
Legend:
Protein
RNA
Selected Interactor(s)
Interactions Browser

Please see the Physical Interaction reports below for full details
MIST Molecular Interaction Search Tool

Please see the Physical Interaction reports below for full details
protein-protein
Physical Interaction
Assay
References
Summary of Genetic Interactions
esyN Network Diagram
Show/hide secondary interactors 
(data from AllianceMine provided by esyN)
esyN Network Key:
Suppression
Enhancement

Please look at the allele data for full details of the genetic interactions
Starting gene(s)
Interaction type
Interacting gene(s)
Reference
Starting gene(s)
Interaction type
Interacting gene(s)
Reference
External Data
Linkouts
DroID - A comprehensive database of gene and protein interactions.
MIST (genetic) - An integrated Molecular Interaction Database
MIST (protein-protein) - An integrated Molecular Interaction Database
Pathways
Signaling Pathways (FlyBase)
Metabolic Pathways
External Data
Linkouts
KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
SignaLink - A signaling pathway resource with multi-layered regulatory networks.
Genomic Location and Detailed Mapping Data
Chromosome (arm)
3R
Recombination map
3-54
Cytogenetic map
Sequence location
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
87F7-87F9
Limits computationally determined from genome sequence between P{lacW}B52s2249&P{lacW}flflL4179 and P{PZ}flfl01949
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
Experimentally Determined Recombination Data
Location
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (15)
Genomic Clones (24)
cDNA Clones (145)
 

Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see JBrowse for alignment of the cDNAs and ESTs to the gene model.

cDNA clones, fully sequenced
BDGP DGC clones
Other clones
Drosophila Genomics Resource Center cDNA clones

For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

cDNA Clones, End Sequenced (ESTs)
RNAi and Array Information
Linkouts
DRSC - Results frm RNAi screens
Antibody Information
Laboratory Generated Antibodies
Commercially Available Antibodies
 
Cell Line Information
Publicly Available Cell Lines
 
    Other Stable Cell Lines
     
      Other Comments

      The kinase activity of lkb1 is essential for its genetic interaction with Sln.

      BrdU incorporation analysis and phosphohistone H3 immunostaining reveal that lkb1 expression does not affect G1/S or G2/M cell cycle progression.

      lkb1 induces apoptotic cell death but not cell cycle arrest.

      lkb1 regulates organ size of the central nervous system by inducing developmental apoptosis during embryogenesis.

      lkb1 is upstream of grim, rpr, and W in the pro-apoptotic pathway.

      p53 is dispensable for lkb1-dependent apoptosis and vice versa.

      lkb1-induced apoptosis is caspase-dependent.

      The tumor-suppressing activity of lkb1 is unrelated to the negative regulation of cell growth control.

      When dsRNA constructs are made and transiently transfected into S2 cells in RNAi experiments, a whole range of mitotic abnormalities, centrosome abnormalities and spindle abnormalities are seen.

      dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.

      Identification: lkb1 was identified in a genetic screen for germ-line clone mutants that disrupt the localization of the product of the transgene stauαTub67C.T:Avic\GFP-m6 in the oocyte.

      lkb1 is required for early A-P polarity of the oocyte and for the repolarization of the oocyte cytoskeleton that defines the embryonic A-P axis.

      Identification: in a germline clone screen for mutants that are defective in localisation of an Avic\GFP-stau marker in living oocytes. 2 alleles of lkb1 have been identified in the screen.

      Relationship to Other Genes
      Source for database merge of

      Source for merge of: CG9374 anon- EST:Posey135

      Additional comments
      Nomenclature History
      Source for database identify of

      Source for identity of: lkb1 CG9374

      Source for identity of: Lkb1 lkb1

      Nomenclature comments
      Etymology
      Synonyms and Secondary IDs (16)
      Reported As
      Symbol Synonym
      LKB1/PEUTZ JEGHERS KINASE
      anon-EST:Posey135
      par-4
      Name Synonyms
      Secondary FlyBase IDs
      • FBgn0027757
      • FBgn0045844
      Datasets (0)
      Study focus (0)
      Experimental Role
      Project
      Project Type
      Title
      Study result (0)
      Result
      Result Type
      Title
      External Crossreferences and Linkouts ( 65 )
      Sequence Crossreferences
      NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.
      GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
      GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.
      RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.
      UniProt/GCRP - The gene-centric reference proteome (GCRP) provides a 1:1 mapping between genes and UniProt accessions in which a single 'canonical' isoform represents the product(s) of each protein-coding gene.
      UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
      Other crossreferences
      AlphaFold DB - AlphaFold provides open access to protein structure predictions for the human proteome and other key proteins of interest, to accelerate scientific research.
      BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
      DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
      EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
      FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
      FlyMine - An integrated database for Drosophila genomics
      KEGG Genes - Molecular building blocks of life in the genomic space.
      MARRVEL_MODEL - MARRVEL (model organism gene)
      Linkouts
      Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
      DroID - A comprehensive database of gene and protein interactions.
      DRSC - Results frm RNAi screens
      Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
      FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
      FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
      Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
      Flygut - An atlas of the Drosophila adult midgut
      iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
      Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
      KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
      MIST (genetic) - An integrated Molecular Interaction Database
      MIST (protein-protein) - An integrated Molecular Interaction Database
      SignaLink - A signaling pathway resource with multi-layered regulatory networks.
      References (131)