HAP2_TETTH
ID HAP2_TETTH Reviewed; 742 AA.
AC A0A060A682;
DT 10-MAY-2017, integrated into UniProtKB/Swiss-Prot.
DT 03-SEP-2014, sequence version 1.
DT 03-AUG-2022, entry version 20.
DE RecName: Full=Hapless 2;
DE AltName: Full=Generative cell specific-1;
DE Flags: Precursor;
GN Name=HAP2 {ECO:0000303|PubMed:28238660, ECO:0000312|EMBL:AIA57699.1};
GN Synonyms=GCS1 {ECO:0000303|PubMed:28238660};
OS Tetrahymena thermophila.
OC Eukaryota; Sar; Alveolata; Ciliophora; Intramacronucleata;
OC Oligohymenophorea; Hymenostomatida; Tetrahymenina; Tetrahymenidae;
OC Tetrahymena.
OX NCBI_TaxID=5911 {ECO:0000312|EMBL:AIA57699.1};
RN [1] {ECO:0000312|EMBL:AIA57699.1}
RP NUCLEOTIDE SEQUENCE [MRNA], DEVELOPMENTAL STAGE, FUNCTION, AND SUBCELLULAR
RP LOCATION.
RX PubMed=25155508; DOI=10.1016/j.cub.2014.07.064;
RA Cole E.S., Cassidy-Hanley D., Fricke Pinello J., Zeng H., Hsueh M.,
RA Kolbin D., Ozzello C., Giddings T. Jr., Winey M., Clark T.G.;
RT "Function of the Male-Gamete-Specific Fusion Protein HAP2 in a Seven-Sexed
RT Ciliate.";
RL Curr. Biol. 24:2168-2173(2014).
RN [2]
RP REVIEW.
RX PubMed=20080406; DOI=10.1016/j.tcb.2009.12.007;
RA Wong J.L., Johnson M.A.;
RT "Is HAP2-GCS1 an ancestral gamete fusogen?";
RL Trends Cell Biol. 20:134-141(2010).
RN [3]
RP FUNCTION, REGION, DOMAIN, AND MUTAGENESIS OF 131-PHE--TYR-133;
RP 147-CYS-CYS-148; 152-LEU--THR-179; ARG-164 AND 171-LEU--LEU-173.
RX PubMed=28238660; DOI=10.1016/j.cub.2017.01.049;
RA Pinello J.F., Lai A.L., Millet J.K., Cassidy-Hanley D., Freed J.H.,
RA Clark T.G.;
RT "Structure-Function Studies Link Class II Viral Fusogens with the Ancestral
RT Gamete Fusion Protein HAP2.";
RL Curr. Biol. 27:651-660(2017).
CC -!- FUNCTION: During fertilization, required for the formation of
CC intercellular membrane pores and subsequent exchange of gametic
CC pronuclei between cells. Probably initiates the formation of
CC intercellular membrane pores by inserting part of its extracellular
CC domain into the cell membrane of the adjoining cell in the mating pair.
CC Mating requires the presence of HAP2 on at least one of the two cells.
CC Mating efficiency is high when HAP2 is present on both cells, and is
CC strongly reduced when HAP2 is present on only one of the two cells.
CC {ECO:0000269|PubMed:25155508, ECO:0000269|PubMed:28238660}.
CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000305|PubMed:25155508,
CC ECO:0000305|PubMed:28238660}; Single-pass type I membrane protein
CC {ECO:0000255}. Cell junction {ECO:0000269|PubMed:25155508,
CC ECO:0000269|PubMed:28238660}. Note=Detected at the mating junction.
CC {ECO:0000269|PubMed:25155508, ECO:0000269|PubMed:28238660}.
CC -!- DEVELOPMENTAL STAGE: Detected in all seven mating types.
CC {ECO:0000269|PubMed:25155508}.
CC -!- DOMAIN: The region that is important for membrane fusion binds to
CC lipids and can insert itself into lipid membranes. It is unstructured
CC in an aqueous environment and assumes a more ordered, beta-stranded
CC conformation in the presence of lipid membranes.
CC {ECO:0000269|PubMed:28238660}.
CC -!- MISCELLANEOUS: HAP2/GCS1 family members mediate membrane fusion between
CC gametes in a broad range of eukaryotes, ranging from algae and higher
CC plants to protozoans and cnidaria, suggesting they are derived from an
CC ancestral gamete fusogen (PubMed:20080406). They function similar to
CC viral fusogens, by inserting part of their extracellular domain into
CC the lipid bilayer of an adjoining cell (PubMed:28238660).
CC {ECO:0000269|PubMed:28238660, ECO:0000303|PubMed:20080406}.
CC -!- SIMILARITY: Belongs to the HAP2/GCS1 family. {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; KJ629172; AIA57699.1; -; mRNA.
DR AlphaFoldDB; A0A060A682; -.
DR SMR; A0A060A682; -.
DR GO; GO:0005911; C:cell-cell junction; IDA:UniProtKB.
DR GO; GO:0016021; C:integral component of membrane; IEA:UniProtKB-KW.
DR GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell.
DR GO; GO:0140522; F:fusogenic activity; IDA:GO_Central.
DR GO; GO:0008289; F:lipid binding; IEA:UniProtKB-KW.
DR GO; GO:0009566; P:fertilization; IMP:GO_Central.
DR GO; GO:0045026; P:plasma membrane fusion; IMP:UniProtKB.
DR GO; GO:0007338; P:single fertilization; IMP:UniProtKB.
DR InterPro; IPR040326; HAP2/GCS1.
DR InterPro; IPR018928; HAP2/GCS1_dom.
DR PANTHER; PTHR31764; PTHR31764; 1.
DR Pfam; PF10699; HAP2-GCS1; 1.
PE 1: Evidence at protein level;
KW Cell junction; Cell membrane; Disulfide bond; Fertilization; Lipid-binding;
KW Membrane; Signal; Transmembrane; Transmembrane helix.
FT SIGNAL 1..19
FT /evidence="ECO:0000255"
FT CHAIN 20..742
FT /note="Hapless 2"
FT /evidence="ECO:0000255"
FT /id="PRO_5001584807"
FT TOPO_DOM 20..540
FT /note="Extracellular"
FT /evidence="ECO:0000305"
FT TRANSMEM 541..561
FT /note="Helical"
FT /evidence="ECO:0000255"
FT TOPO_DOM 562..742
FT /note="Cytoplasmic"
FT /evidence="ECO:0000305"
FT REGION 152..179
FT /note="Important for membrane fusion"
FT /evidence="ECO:0000269|PubMed:28238660"
FT DISULFID 30..40
FT /evidence="ECO:0000250|UniProtKB:A4GRC6"
FT DISULFID 118..147
FT /evidence="ECO:0000250|UniProtKB:A4GRC6"
FT DISULFID 129..182
FT /evidence="ECO:0000250|UniProtKB:A4GRC6"
FT DISULFID 148..312
FT /evidence="ECO:0000250|UniProtKB:A4GRC6"
FT DISULFID 150..168
FT /evidence="ECO:0000250|UniProtKB:A4GRC6"
FT DISULFID 295..319
FT /evidence="ECO:0000250|UniProtKB:A4GRC6"
FT DISULFID 431..470
FT /evidence="ECO:0000250|UniProtKB:A4GRC6"
FT MUTAGEN 131..133
FT /note="FQY->AAA: No effect."
FT /evidence="ECO:0000269|PubMed:28238660"
FT MUTAGEN 147..148
FT /note="CC->SS: Loss of function in mediating cell fusion."
FT /evidence="ECO:0000269|PubMed:28238660"
FT MUTAGEN 152..179
FT /note="Missing: Loss of function in mediating cell fusion."
FT /evidence="ECO:0000269|PubMed:28238660"
FT MUTAGEN 164
FT /note="R->A: No effect."
FT /evidence="ECO:0000269|PubMed:28238660"
FT MUTAGEN 171..173
FT /note="LNL->AAA: No effect."
FT /evidence="ECO:0000269|PubMed:28238660"
SQ SEQUENCE 742 AA; 82663 MW; 8C166CB44EE5C714 CRC64;
MKFLAFGLIY FHFCILNRCE YITSSTIQKC YNSSNEPNNC SQKAVIVLSL ENGQIANTEQ
VVATLNQLSD SGVNKQLQNS FIFEVTKSPV TALFPLIYLQ DFNSQPLEQV IATTLFSCKD
GFYDSSPTCK FQYDSKGQKI LDSQGYCCYC SLSDILGMGN DLSRGKVCYA LNLGAGSATA
HCLKFSPLWY SAFKIQQYQL YFEVNINIYT VDSQNQKNLK QTLKLSTSNP TMKSSDNSTI
SKIIGTFTPT QPPADLSSYY LVKPSFPATD PRVLQGISSW MFVDKTMFTL DGTQCNKIGV
SYSGFRQQSS SCSQPVGSCL QNQLENLYQS DLILLSQNKQ PKYLLESQGN FNQVQFQGQT
ILQQGLSGSA STLITIEIDA AQIKFVTNLG IGCISQCSIN NFESHSGNGK LVALVQNQGN
YSAEFVLGFN CSSNVQPIQG QKLFLTANQL YNFNCSVSVN SDISAINNNC TINLYDAIGN
QLDSKNILFN TTSTNHTSNQ GNNTGQQQSS QEYKSSQSCS DKCSSFWSFW CYFSAGCIKE
AFKSIASIAG VASALALVIF LAKNGYLVPI IRFLCCCCCK SKKKENEKNK DKTDKKSIQE
SCSYDRSCCS HSISQSYQVE NKNKYKRSKI QRSFSSESCQ DKSKKIINEL SNLEETFEAN
KLYANIDKNS SIFEYFGFKK SFTFILYERN DILFLPQNST ILDMIGALQP QKGSYLAQKF
LEIVNKNALK VVSTSPLYLL IE
