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0  structures 68  species 0  interactions 100  sequences 1  architecture

Family: HAP2-GCS1 (PF10699)

Summary: Male gamete fusion factor

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Male gamete fusion factor Provide feedback

The gene encoding Arabidopsis HAP2 is allelic with GCS1 (Generative cell-specific protein 1). HAP2 is expressed only in the haploid sperm and is required for efficient guidance of the pollen tube to the ovules. In Arabidopsis the protein is a predicted membrane protein with an N-terminal secretion signal, a single transmembrane domain and a C-terminal histidine-rich domain [1]. HAP2-GCS1 is found from plants to lower eukaryotes and is necessary for the fusion of the gametes in fertilisation. It is involved in a novel mechanism for gamete fusion where a first species-specific protein binds male and female gamete membranes together after which a second, broadly conserved protein, either directly or indirectly, causes fusion of the two membranes together. The broadly conserved protein is represented by this HAP2-GCS1 domain, conserved from plants to lower eukaryotes [2]. In Plasmodium berghei the protein is expressed only in male gametocytes and gametes, having a male-specific function during the interaction with female gametes, and being indispensable for parasite fertilisation. The gene in plants and eukaryotes might well have originated from acquisition of plastids from red algae [3].

Literature references

  1. von Besser K, Frank AC, Johnson MA, Preuss D; , Development. 2006;133:4761-4769.: Arabidopsis HAP2 (GCS1) is a sperm-specific gene required for pollen tube guidance and fertilization. PUBMED:17079265 EPMC:17079265

  2. Liu Y, Tewari R, Ning J, Blagborough AM, Garbom S, Pei J, Grishin NV, Steele RE, Sinden RE, Snell WJ, Billker O; , Genes Dev. 2008;22:1051-1068.: The conserved plant sterility gene HAP2 functions after attachment of fusogenic membranes in Chlamydomonas and Plasmodium gametes. PUBMED:18367645 EPMC:18367645

  3. Hirai M, Arai M, Mori T, Miyagishima SY, Kawai S, Kita K, Kuroiwa T, Terenius O, Matsuoka H; , Curr Biol. 2008;18:607-613.: Male fertility of malaria parasites is determined by GCS1, a plant-type reproduction factor. PUBMED:18403203 EPMC:18403203


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR018928

The gene encoding Arabidopsis HAP2 is allelic with GCS1 (Generative cell-specific protein 1). HAP2 is expressed only in the haploid sperm and is required for efficient guidance of the pollen tube to the ovules. In Arabidopsis the protein is a predicted membrane protein with an N-terminal secretion signal, a single transmembrane domain and a C-terminal histidine-rich domain [PUBMED:17079265]. HAP2-GCS1 is found from plants to lower eukaryotes and is necessary for the fusion of the gametes in fertilisation. It is involved in a novel mechanism for gamete fusion where a first species-specific protein binds male and female gamete membranes together after which a second, broadly conserved protein, either directly or indirectly, causes fusion of the two membranes together. The broadly conserved protein is represented by this HAP2-GCS1 domain, conserved from plants to lower eukaryotes [PUBMED:18367645]. In Plasmodium berghei the protein is expressed only in male gametocytes and gametes, having a male-specific function during the interaction with female gametes, and being indispensable for parasite fertilisation. The gene in plants and eukaryotes might well have originated from acquisition of plastids from red algae [PUBMED:18403203].

Domain organisation

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Alignments

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  Seed
(22)
Full
(100)
Representative proteomes NCBI
(107)
Meta
(1)
RP15
(30)
RP35
(46)
RP55
(62)
RP75
(69)
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  Seed
(22)
Full
(100)
Representative proteomes NCBI
(107)
Meta
(1)
RP15
(30)
RP35
(46)
RP55
(62)
RP75
(69)
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You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

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Curation and family details

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Curation View help on the curation process

Seed source: Billker O
Previous IDs: none
Type: Domain
Author: Bateman A, Coggill P
Number in seed: 22
Number in full: 100
Average length of the domain: 48.30 aa
Average identity of full alignment: 38 %
Average coverage of the sequence by the domain: 6.85 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 19.7 19.7
Trusted cut-off 20.2 26.6
Noise cut-off 19.4 19.0
Model length: 49
Family (HMM) version: 4
Download: download the raw HMM for this family

Species distribution

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