Gene Dmel\Top1

13C1-13C1

(determined by in situ hybridisation)

Experimentally Determined Recombination Data

Location

(Hsieh, 1992.12.10)

Left of (cM)

Right of (cM)

Notes

Molecular Map Data

Gene Order (in direction of increasing cytology)

References

In direction of increasing cytology: Top1? dah?

(Zhang et al., 1996)

Gene Order (overall orientation not stated)

References

Overall orientation not stated: Top1+ dah+

(Brown et al., 1998, Brown, 1996.11.26)

Gene Model & Products

Please see the GBrowse view of Dmel\Top1 for information on other features

Comments on Gene Model

It appears that the final break in M74557 and genomic sequence U80064 is a sequence difference between strains because it is not referred to as an intron in FBrf0102653 and appears as a break in the genomic sequence. It doesn't not have conserved splice boundaries and was not annotated as a splice.

Transcript Data

Annotated Transcripts

Name

FlyBase ID

RefSeq ID

Length (nt)

Associated CDS (aa)

Top1-RA

FBtr0074005

NM_078606

5325

974

Top1-RB

FBtr0074006

NM_167435

2379

581

Top1-RC

FBtr0100294

NM_001014742

4940

974

Additional Transcript Data & Comments

Reported size (kB)

5.2, 4.0 (unknown)

5.2, 4.0 (northern blot)

Comments

The 5.2kb Top1 transcripts do not show diversity at the 3\\' end as do the maternal Top1 transcripts.

Among the maternal Top1 transcripts, some have an additional 385bp intron spliced out of the 3\\' untranslated region.

Top1 transcripts ranging from 3.8kb-4.2kb differ in the sites of polyadenylation and are specifically expressed in ovaries. At least 12 different sites of polyadenylation have been observed.

External Data

Crossreferences

Polypeptide Data

Annotated Polypeptides

Name

FlyBase ID

Predicted MW (kD)

Length (aa)

Theoretical pI

RefSeq ID

GenBank protein

Top1-PA

FBpp0073822

111.9

974

9.55

NP_511161

AAF48440

Top1-PB

FBpp0073823

68.6

581

9.56

NP_727841

AAN09660

Top1-PC

FBpp0099689

111.9

974

9.55

NP_001014742

AAX52496

Additional Polypeptide Data & Comments

Reported size (kD)

972 (aa); 135 (kD)

135 (kD)

972 (aa)

Comments

Homology to other Top1 proteins is concentrated in two regions. The Drosophila enzyme is larger than the enzymes from yeast and human and is uniquely characterized by a Ser/His rich hydrophilic domain of 200aa at its amino terminus. The bacterially expressed protein was shown to have classic eukaryotic DNA topoisomerase I activity, distinguished by the fact that it can relax both positively and negatively supercoiled DNA in the absence of a divalent cation.

(BDGP Project Members, 2000-)

Camptothecin-induced Top1 protein cleavage sites were mapped in the Act5C, Act57B, and hsp70 genes. Top1 protein cleavage sites were localized to the transcribed portions of the Hsp70B and Act5C genes, and only when they are transcriptionally active. None were found in a transcriptionally inactive Act57B gene.

(Kroeger and Rowe, 1992)

External Data

Linkouts

PANTHER - Protein classification by function, families, and pathways

•

FBgn0004924

Crossreferences

InterPro domains - A database of protein families, domains, and functional sites

•

DNA topoisomerase I, DNA binding, mixed alpha/beta motif, eukaryotic-type (IPR013030)

DNA topoisomerase I, catalytic core, alpha-helical subdomain, eukaryotic-type (IPR014711)

DNA topoisomerase I, catalytic core, alpha/beta subdomain, eukaryotic-type (IPR014727)

DNA topoisomerase I, C-terminal (IPR001631)

DNA topoisomerase I, DNA binding, eukaryotic-type (IPR008336)

DNA topoisomerases I, dispensable insert, eukaryotic-type (IPR009054)

DNA breaking-rejoining enzyme, catalytic core (IPR011010)

DNA topoisomerase I, C-terminal, eukaryotic-type (IPR013499)

DNA topoisomerase I, catalytic core, eukaryotic-type (IPR013500)

Sequences Consistent with the Gene Model

DDBJ /
EMBL /
GenBank

DNA sequence

Protein sequence

Name

P30189

UniProtKB/TrEMBL

Q8IR39

Maps to

Does NOT map to

Identified with

RE58921

Mapped Features & Mutations

Please see GBrowse or insertion reports for information on insertions of transgenic constructs and features not listed here

Type

Symbol & Location

Additional Notes

References

point mutation

Top1[77]
X:15,221,482..15,222,563

comment=3kb insertion (identity unspecified) in 3' untranslated region of Top1. The insertion site falls within a SalI-BamHI fragment according the the map in Figure 1 of FBrf0089875.
evidence=experimental
linked_to=SalI-BamHI_rfrag

(Lee et al., 1993, Zhang et al., 1996)

rescue fragment

Top1[+t10]
X:15,212,195..15,222,563

comment=Position of rescue fragment on reference sequence inferred by FlyBase curator
evidence=experimental
linked_to=SpeI-BamHI_rfrag

External Data

Linkouts

DEDB - Drosophila exon database: splicing graphs

•

2882

Crossreferences

Expression Data

FlyBase-Curated Data

Transcript and
Protein data

Please see the FlyBase Gene Expression Report for details of gene expression from the literature.

Summary of Transcript Expression

Stage

Tissue/Position

Reference

adult stage

embryonic stage

embryonic stage | early

adult stage | female

ovary

embryonic stage-adult stage

embryonic stage

adult stage | female

ovary

Marker for

Subcellular Localization

CV Term

Summary of Polypeptide Expression

Stage

Tissue/Position

Reference

embryonic stage-adult stage

mitotic cell cycle defective

Marker for

Subcellular Localization

CV Term

External Data & Images

Linkouts

FLIGHT - Cell culture data for RNAi and other high-throughput technologies

•

FBgn0004924

FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array

•

FBgn0004924

GEO (NCBI) - Gene expression data: microarray and other high-throughput technologies

•

FBgn0004924

Alleles & Phenotypes

Summary of Allele Phenotypes

Lethality

Allele

viable

Top1^CC01414

lethal | recessive

lethal | larval stage

lethal | larval stage | recessive

Top1⁷⁷

lethal | prepupal stage

Top1^G0134

lethal | pupal stage

Top1^G0134

lethal | pharate adult stage

Top1^G0278

semi-lethal

Top1^G0229

semi-lethal | recessive

Top1^G0229

Other Phenotypes

Allele

wild-type

cell death defective

Top1⁷⁷

Top1⁷⁷

mitotic cell cycle defective, with Top1⁷⁷

Top1^hs.2

mitotic cell cycle defective, with Top1^hs.2

Top1⁷⁷

melanotic 'tumor'

Top1^G0134

melanotic 'tumor' | larval stage

Top1^G0201

Sterility

Allele

female sterile

Top1⁷⁷

Phenotype manifest in

Allele

dorsal appendage, with Top1^hs.2

Top1⁷⁷

follicle cell, with Top1^hs.2

Top1⁷⁷

germarium, with Top1^hs.2

Top1⁷⁷

mitotic cell cycle, with Top1^hs.2

Top1⁷⁷

nurse cell & nucleus, with Top1^hs.2

Top1⁷⁷

nurse cell | ectopic, with Top1^hs.2

Top1⁷⁷

oocyte, with Top1^hs.2

Top1⁷⁷

oocyte | ectopic, with Top1^hs.2

Top1⁷⁷

syncytial blastoderm embryo & mitotic cell cycle, with Top1^hs.2

Top1⁷⁷

syncytial blastoderm embryo & mitotic telophase, with Top1^hs.2

Top1⁷⁷

syncytial blastoderm embryo & nucleus, with Top1^hs.2

Top1⁷⁷

larva

Top1⁷⁷

imaginal disc

Top1⁷⁷

melanotic mass

wing

Top1^G0278

chaeta

Top1^G0278

dorsal appendage, with Top1⁷⁷

Top1^hs.2

follicle cell, with Top1⁷⁷

Top1^hs.2

germarium, with Top1⁷⁷

Top1^hs.2

mitotic cell cycle, with Top1⁷⁷

Top1^hs.2

nurse cell & nucleus, with Top1⁷⁷

Top1^hs.2

nurse cell | ectopic, with Top1⁷⁷

Top1^hs.2

oocyte, with Top1⁷⁷

Top1^hs.2

oocyte | ectopic, with Top1⁷⁷

Top1^hs.2

syncytial blastoderm embryo & mitotic cell cycle, with Top1⁷⁷

Top1^hs.2

syncytial blastoderm embryo & mitotic telophase, with Top1⁷⁷

Top1^hs.2

syncytial blastoderm embryo & nucleus, with Top1⁷⁷

Top1^hs.2

syncytial blastoderm embryo & nucleus

Top1^hs.2

syncytial blastoderm embryo & mitotic cell cycle

Top1^hs.2

Classical Alleles ( 11 )

For All Classical Alleles Show

Allele of Top1	Class	Mutagen	Stocks	Known lesion
Top1¹¹¹		Δ2-3	0	--
Top1¹¹²		Δ2-3	1	--
Top1¹¹³		Δ2-3	0	--
Top1⁷⁷	loss of function	Δ2-3	3	Yes
Top1^CC01414		P-element activity	0	Yes
Top1^G0134		P-element activity	1	--
Top1^G0201		P-element activity	1	--
Top1^G0229		P-element activity	1	--
Top1^G0278		P-element activity	1	--
Top1^Wee-P153			0	Yes
Top1^c03129		piggyBac transposase	0	--

Alleles Carried on Transgenic Constructs ( 10 )

For All Alleles Carried on Transgenic Constructs Show

Allele of Top1	Mutagen	Stocks	Known lesion
Top1^+t10	in vitro construct \| genomic fragment	1	Yes
Top1^+t13.7	in vitro construct \| genomic fragment	0	Yes
Top1^{313.T:Ecol\lacZ}	in vitro construct \| coding region fusion	0	Yes
Top1^GD4574	in vitro construct \| RNAi in vitro construct \| regulatory fusion	1	Yes
Top1^{NF315.Hsp83.T:Ecol\lacZ}	in vitro construct \| regulatory fusion in vitro construct \| coding region fusion	0	Yes
Top1^{NF438.Hsp83.T:Ecol\lacZ}	in vitro construct \| regulatory fusion in vitro construct \| coding region fusion	0	Yes
Top1^{NF582.Hsp83.T:Ecol\lacZ}	in vitro construct \| regulatory fusion in vitro construct \| coding region fusion	0	Yes
Top1^{NF964.Hsp83.T:Ecol\lacZ}	in vitro construct \| regulatory fusion in vitro construct \| coding region fusion	0	Yes
Top1^hs.2	in vitro construct \| regulatory fusion	0	Yes
Top1^hs.6	in vitro construct \| regulatory fusion	0	Yes

Aneuploid Aberrations

Useful deficiency

T(1;3)143-3

Disrupted in

Df(1)dah³⁰

(Zhang et al., 1996)

Transgenic Constructs & Insertions

Transgenic Constructs

Type of construct

Name

Expression data

reporter construct

P{Hsp83-Top1-lacZ.NF315}

P{Hsp83-Top1-lacZ.NF438}

P{Hsp83-Top1-lacZ.NF582}

P{Hsp83-Top1-lacZ.NF964}

P{Top1-lacZ}

UAS construct

P{GD4574}

characterization construct

heat-shock construct

P{Hsp83-Top1-lacZ.NF315}

P{Hsp83-Top1-lacZ.NF438}

P{Hsp83-Top1-lacZ.NF582}

P{Hsp83-Top1-lacZ.NF964}

Insertions

Type of insertions

Name

Expression data

miscellaneous insertions

PBac{PB}Top1^c03129

P{PTT-GC}Top1^CC01414

P{Wee-P.ph0}Top1^Wee-P153

insertion of enhancer trap

Related Comments

Please look at the allele reports for the complete phenotype data

Top1 enzyme has been purified and characterised.

(Javaherian et al., 1982)

Top1 has been isolated and partially characterised.

(Chakravarti et al., 1992)

The interaction of Top1 and Top2 gene products with transcriptionally active and inactive Act5C, Act57B and Hsp70B has been compared. Topoisomerase I binding sites are found in the transcribed portions of the Hsp70B and Act5C genes, and only when they are transcriptionally active. It does not associate with a transcriptionally inactive Act57B gene.

(Kroeger and Rowe, 1992)

DNA topoisomerase 1 was cloned by homology to consensus eukaryotic DNA topoisomerase 1 sequence, and expressed in an E.coli expression system.

Using P element mutagenesis a mutant deficient in topoisomerase 1 was generated: topoisomerase 1 is essential for growth and development.