F4JP36 · HAP2_ARATH
- ProteinProtein HAPLESS 2
- GeneHAP2
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids705 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Required for male fertility (PubMed:17079265, PubMed:20333238).
Plays a role in pollen tube guidance and successful gamete attachment (PubMed:17079265).
Essential for the fusion of gametes during double fertilization, where one male gamete fuses with the egg to produce a zygote, and another male gamete fuses with the central cell to produce the endosperm (PubMed:17079265, PubMed:20333238, PubMed:21209845).
Mediates the fusion of cell membranes (PubMed:28137780).
Not required for pollen tube outgrowth (PubMed:17079265, PubMed:20333238).
Plays a role in pollen tube guidance and successful gamete attachment (PubMed:17079265).
Essential for the fusion of gametes during double fertilization, where one male gamete fuses with the egg to produce a zygote, and another male gamete fuses with the central cell to produce the endosperm (PubMed:17079265, PubMed:20333238, PubMed:21209845).
Mediates the fusion of cell membranes (PubMed:28137780).
Not required for pollen tube outgrowth (PubMed:17079265, PubMed:20333238).
Miscellaneous
HAP2/GCS1 family members mediate membrane fusion between gametes in a broad range of eukaryotes, ranging from algae and higher plants to protozoans and cnidaria, suggesting they are derived from an ancestral gamete fusogen. They function similar to viral fusogens, by inserting part of their extracellular domain into the lipid bilayer of an adjoining cell.
GO annotations
all annotations | all molecular function | nucleotide binding | molecular_function | nucleic acid binding | dna binding | chromatin binding | dna-binding transcription factor activity | rna binding | cytoskeletal motor activity | catalytic activity | nuclease activity | signaling receptor binding | structural molecule activity | transporter activity | binding | protein binding | translation factor activity, rna binding | lipid binding | kinase activity | transferase activity | hydrolase activity | oxygen binding | enzyme regulator activity | carbohydrate binding | signaling receptor activity | translation regulator activity | transcription regulator activity | other molecular function | all biological process | carbohydrate metabolic process | generation of precursor metabolites and energy | nucleobase-containing compound metabolic process | dna metabolic process | translation | lipid metabolic process | transport | response to stress | cell cycle | cell communication | signal transduction | cell-cell signaling | multicellular organism development | circadian rhythm | biological_process | metabolic process | catabolic process | biosynthetic process | response to light stimulus | response to external stimulus | tropism | response to biotic stimulus | response to abiotic stimulus | response to endogenous stimulus | embryo development | post-embryonic development | fruit ripening | abscission | pollination | flower development | cellular process | programmed cell death | photosynthesis | cellular component organization | cell growth | protein metabolic process | cellular homeostasis | secondary metabolic process | reproductive process | cell differentiation | protein modification process | growth | epigenetic regulation of gene expression | response to chemical | anatomical structure development | regulation of molecular function | other biological process | all cellular component | cellular_component | extracellular region | cell wall | intracellular anatomical structure | nucleus | nuclear envelope | nucleoplasm | nucleolus | cytoplasm | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | cytosol | ribosome | cytoskeleton | plasma membrane | chloroplast | plastid | thylakoid | membrane | external encapsulating structure | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | endoplasmic reticulum | |
Cellular Component | endoplasmic reticulum membrane | |
Cellular Component | plasma membrane | |
Molecular Function | lipid binding | |
Biological Process | double fertilization forming a zygote and endosperm | |
Biological Process | fusion of sperm to egg plasma membrane involved in double fertilization forming a zygote and endosperm | |
Biological Process | plasma membrane fusion | |
Biological Process | pollen sperm cell differentiation | |
Biological Process | pollen tube guidance |
Keywords
- Biological process
- Ligand
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameProtein HAPLESS 2
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > malvids > Brassicales > Brassicaceae > Camelineae > Arabidopsis
Accessions
- Primary accessionF4JP36
- Secondary accessions
Proteomes
Organism-specific databases
Genome annotation databases
Subcellular Location
UniProt Annotation
GO Annotation
Endoplasmic reticulum membrane ; Single-pass membrane protein
Cell membrane ; Single-pass type I membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 25-561 | Extracellular | ||||
Sequence: IQILSKSKLEKCEKTSDSGNLNCSTKIVLNLAVPSGSSGGEASIVAEIVEVEDNSSSNMQTVRIPPVITVNKSAAYALYDLTYIRDVPYKPQEYHVTTRKCEHDAGPDIVQICERLRDEKGNVLEQTQPICCPCGPQRRMPSSCGDIFDKMIKGKANTAHCLRFPGDWFHVFGIGQRSLGFSVRVELKTGTRVSEVIIGPENRTATANDNFLKVNLIGDFGGYTSIPSFEDFYLVIPREAAEAGQPGSLGANYSMWMLLERVRFTLDGLECNKIGVGYEAFNTQPNFCSSPYWSCLHNQLWNFRESDINRIDRHQLPLYGLEGRFERINQHPNAGPHSFSIGVTETLNTNLMIELRADDIEYVFQRSPGKIINIAIPTFEALTQFGVAAVIIKNTGEVEASYSLTFDCSKGVAFVEEQFFIIKPKAVTTRSFKLYPTKDQAAKYICTAILKDSQFSEVDRAECQFSTTATVLDNGTQVTNPFQIPETQPKGFFDSIRILWTKIINGLVDFITGDTCRNKCSSFFDFSCHIQYVCLSW | ||||||
Transmembrane | 562-582 | Helical | ||||
Sequence: MVMFGLLLALFPITCLLLWLL | ||||||
Topological domain | 583-705 | Cytoplasmic | ||||
Sequence: HQKGLFDPCYDWWEDHFDLDHHRRLLPSRADVVNRHHHHHKHRHHHNHHRRTHQRHKHHHGQDDDVLQKMMLERDHSDSHYYHQLHRVHKDSKQKQRRRAKHGIVLPRDVHVERQRKQRLRES |
Keywords
- Cellular component
Phenotypes & Variants
Disruption phenotype
Defective in pollen tube guidance. Prevents gamete interaction and fertilization, resulting in male sterility.
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 125 variants from UniProt as well as other sources including ClinVar and dbSNP.
PTM/Processing
Features
Showing features for signal, chain, disulfide bond, glycosylation.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-24 | |||||
Sequence: MVNAILMACILAGIFVGMFNEVDG | ||||||
Chain | PRO_0000416780 | 25-705 | Protein HAPLESS 2 | |||
Sequence: IQILSKSKLEKCEKTSDSGNLNCSTKIVLNLAVPSGSSGGEASIVAEIVEVEDNSSSNMQTVRIPPVITVNKSAAYALYDLTYIRDVPYKPQEYHVTTRKCEHDAGPDIVQICERLRDEKGNVLEQTQPICCPCGPQRRMPSSCGDIFDKMIKGKANTAHCLRFPGDWFHVFGIGQRSLGFSVRVELKTGTRVSEVIIGPENRTATANDNFLKVNLIGDFGGYTSIPSFEDFYLVIPREAAEAGQPGSLGANYSMWMLLERVRFTLDGLECNKIGVGYEAFNTQPNFCSSPYWSCLHNQLWNFRESDINRIDRHQLPLYGLEGRFERINQHPNAGPHSFSIGVTETLNTNLMIELRADDIEYVFQRSPGKIINIAIPTFEALTQFGVAAVIIKNTGEVEASYSLTFDCSKGVAFVEEQFFIIKPKAVTTRSFKLYPTKDQAAKYICTAILKDSQFSEVDRAECQFSTTATVLDNGTQVTNPFQIPETQPKGFFDSIRILWTKIINGLVDFITGDTCRNKCSSFFDFSCHIQYVCLSWMVMFGLLLALFPITCLLLWLLHQKGLFDPCYDWWEDHFDLDHHRRLLPSRADVVNRHHHHHKHRHHHNHHRRTHQRHKHHHGQDDDVLQKMMLERDHSDSHYYHQLHRVHKDSKQKQRRRAKHGIVLPRDVHVERQRKQRLRES | ||||||
Disulfide bond | 36↔47 | |||||
Sequence: CEKTSDSGNLNC | ||||||
Glycosylation | 46 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 78 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 95 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 125↔155 | |||||
Sequence: CEHDAGPDIVQICERLRDEKGNVLEQTQPIC | ||||||
Disulfide bond | 137↔185 | |||||
Sequence: CERLRDEKGNVLEQTQPICCPCGPQRRMPSSCGDIFDKMIKGKANTAHC | ||||||
Disulfide bond | 156↔312 | |||||
Sequence: CPCGPQRRMPSSCGDIFDKMIKGKANTAHCLRFPGDWFHVFGIGQRSLGFSVRVELKTGTRVSEVIIGPENRTATANDNFLKVNLIGDFGGYTSIPSFEDFYLVIPREAAEAGQPGSLGANYSMWMLLERVRFTLDGLECNKIGVGYEAFNTQPNFC | ||||||
Disulfide bond | 158↔168 | |||||
Sequence: CGPQRRMPSSC | ||||||
Glycosylation | 226 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Glycosylation | 276 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | ||||||
Disulfide bond | 295↔319 | |||||
Sequence: CNKIGVGYEAFNTQPNFCSSPYWSC | ||||||
Disulfide bond | 432↔470 | |||||
Sequence: CSKGVAFVEEQFFIIKPKAVTTRSFKLYPTKDQAAKYIC | ||||||
Glycosylation | 498 | N-linked (GlcNAc...) asparagine | ||||
Sequence: N |
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Expressed only in mature pollen, in the two sperm cells.
Developmental stage
Expressed during pollen development and tube growth.
Gene expression databases
Interaction
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for compositional bias, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 617-639 | Basic residues | ||||
Sequence: RHHHHHKHRHHHNHHRRTHQRHK | ||||||
Region | 617-646 | Disordered | ||||
Sequence: RHHHHHKHRHHHNHHRRTHQRHKHHHGQDD | ||||||
Compositional bias | 668-684 | Basic residues | ||||
Sequence: HRVHKDSKQKQRRRAKH | ||||||
Region | 668-705 | Disordered | ||||
Sequence: HRVHKDSKQKQRRRAKHGIVLPRDVHVERQRKQRLRES | ||||||
Compositional bias | 685-705 | Basic and acidic residues | ||||
Sequence: GIVLPRDVHVERQRKQRLRES |
Domain
The N-terminal domain (62-541)and the C-terminal domain (583-705) are both required for functional gamete fusion. A positive charge, and not a conserved primary amino acid sequence, is required for a functional C-terminal domain. The N-terminal domain may be involved in interactions with another membrane-bound protein on female gametes, while positively charged C-terminus may function through electrostatic interactions with the sperm plasma membrane.
Sequence similarities
Belongs to the HAP2/GCS1 family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
- Length705
- Mass (Da)80,505
- Last updated2011-06-28 v1
- Checksum0D4BEF577DDE6786
Sequence caution
Features
Showing features for sequence conflict, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Sequence conflict | 127 | in Ref. 1; AAY51999/AAY51998 and 2; BAE71143 | ||||
Sequence: H → P | ||||||
Compositional bias | 617-639 | Basic residues | ||||
Sequence: RHHHHHKHRHHHNHHRRTHQRHK | ||||||
Compositional bias | 668-684 | Basic residues | ||||
Sequence: HRVHKDSKQKQRRRAKH | ||||||
Compositional bias | 685-705 | Basic and acidic residues | ||||
Sequence: GIVLPRDVHVERQRKQRLRES |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
DQ022375 EMBL· GenBank· DDBJ | AAY51999.1 EMBL· GenBank· DDBJ | mRNA | ||
DQ022676 EMBL· GenBank· DDBJ | AAY51998.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AB206811 EMBL· GenBank· DDBJ | BAE71143.2 EMBL· GenBank· DDBJ | mRNA | ||
AL049500 EMBL· GenBank· DDBJ | CAB39943.1 EMBL· GenBank· DDBJ | Genomic DNA | Sequence problems. | |
AL161532 EMBL· GenBank· DDBJ | CAB78215.1 EMBL· GenBank· DDBJ | Genomic DNA | Sequence problems. | |
CP002687 EMBL· GenBank· DDBJ | AEE83041.1 EMBL· GenBank· DDBJ | Genomic DNA |