UniProt functional annotation for Q8IYV9



	UniProt functional annotation for Q8IYV9

UniProt code: Q8IYV9.

Organism: Homo sapiens (Human).

Taxonomy: Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.

Function: Essential sperm cell-surface protein required for fertilization by acting as a ligand for IZUMO1R/JUNO receptor on egg (PubMed:15759005). The IZUMO1:IZUMO1R/JUNO interaction is a necessary adhesion event between sperm and egg that is required for fertilization but is not sufficient for cell fusion (PubMed:15759005). The ligand- receptor interaction probably does not act as a membrane 'fusogen' (PubMed:15759005). {ECO:0000269|PubMed:15759005}.

Subunit: Monomer (PubMed:27309808, PubMed:27309818). Monomer, homodimer and homooligomer; depending on the context (By similarity). Interacts with IZUMO1R/JUNO. IZUMO1 and IZUMO1R/JUNO form a complex with 1:1 stoichiometry (PubMed:27309808, PubMed:27309818). In gamete recognition, IZUMO1R/JUNO first binds to monomeric IZUMO1 (By similarity). The weak, but specific interaction with IZUMO1R/JUNO induces IZUMO1 homodimerization (By similarity). The process follows a tight binding phase where IZUMO1 bends the entire structure towards the sperm membrane side through a thiol-disulfide exchange reaction (By similarity). The molecule no longer binds to IZUMO1R/JUNO and instead binds to a putative second oocyte receptor (By similarity). Interacts with ACE3 (By similarity). {ECO:0000250|UniProtKB:Q9D9J7, ECO:0000269|PubMed:27309808, ECO:0000269|PubMed:27309818}.

Subcellular location: Cell membrane {ECO:0000269|PubMed:15759005}; Single-pass type I membrane protein {ECO:0000255}. Cytoplasmic vesicle, secretory vesicle, acrosome membrane {ECO:0000250|UniProtKB:Q9D9J7}; Single-pass type I membrane protein {ECO:0000255}. Note=Localizes initially to the acrosome membrane of the sperm head (both outer and inner acrosomal membranes) (By similarity). During the acrosome reaction, translocates to the plasma membrane (PubMed:15759005). {ECO:0000250|UniProtKB:Q9D9J7, ECO:0000269|PubMed:15759005}.

Tissue specificity: Sperm-specific (at protein level) (PubMed:15759005). Detectable on sperm surface only after the acrosome reaction (PubMed:15759005). {ECO:0000269|PubMed:15759005}.

Domain: The extracellular domain assumes a distinct boomerang shape when not bound to IZUMO1R/JUNO (PubMed:27309818). Interaction with IZUMO1R/JUNO triggers a conformation change, so that the IZUMO1 extracellular domain assumes an upright conformation (PubMed:27309818). {ECO:0000269|PubMed:27309818}.

Domain: The cytoplasmic C-terminus region is not essential for fertilization. It is however required for protein stability. {ECO:0000250|UniProtKB:Q9D9J7}.

Ptm: N-glycosylated. Glycosylation is not essential for fusion and for proper protein trafficking in sperm. {ECO:0000250|UniProtKB:Q9D9J7}.

Ptm: Phosphorylated. The cytoplasmic C-terminus is phosphorylated and undergoes phosphorylation changes during epididymal transit. {ECO:0000250|UniProtKB:Q9D9J7}.

Miscellaneous: Izumo is the name of a Japanese shrine to marriage. {ECO:0000305|PubMed:15759005}.

Similarity: Belongs to the Izumo family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Homo sapiens (Human).
Taxonomy:		Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo.



Function:		Essential sperm cell-surface protein required for fertilization by acting as a ligand for IZUMO1R/JUNO receptor on egg (PubMed:15759005). The IZUMO1:IZUMO1R/JUNO interaction is a necessary adhesion event between sperm and egg that is required for fertilization but is not sufficient for cell fusion (PubMed:15759005). The ligand- receptor interaction probably does not act as a membrane 'fusogen' (PubMed:15759005). {ECO:0000269\|PubMed:15759005}.


Subunit:		Monomer (PubMed:27309808, PubMed:27309818). Monomer, homodimer and homooligomer; depending on the context (By similarity). Interacts with IZUMO1R/JUNO. IZUMO1 and IZUMO1R/JUNO form a complex with 1:1 stoichiometry (PubMed:27309808, PubMed:27309818). In gamete recognition, IZUMO1R/JUNO first binds to monomeric IZUMO1 (By similarity). The weak, but specific interaction with IZUMO1R/JUNO induces IZUMO1 homodimerization (By similarity). The process follows a tight binding phase where IZUMO1 bends the entire structure towards the sperm membrane side through a thiol-disulfide exchange reaction (By similarity). The molecule no longer binds to IZUMO1R/JUNO and instead binds to a putative second oocyte receptor (By similarity). Interacts with ACE3 (By similarity). {ECO:0000250\|UniProtKB:Q9D9J7, ECO:0000269\|PubMed:27309808, ECO:0000269\|PubMed:27309818}.
Subcellular location:		Cell membrane {ECO:0000269\|PubMed:15759005}; Single-pass type I membrane protein {ECO:0000255}. Cytoplasmic vesicle, secretory vesicle, acrosome membrane {ECO:0000250\|UniProtKB:Q9D9J7}; Single-pass type I membrane protein {ECO:0000255}. Note=Localizes initially to the acrosome membrane of the sperm head (both outer and inner acrosomal membranes) (By similarity). During the acrosome reaction, translocates to the plasma membrane (PubMed:15759005). {ECO:0000250\|UniProtKB:Q9D9J7, ECO:0000269\|PubMed:15759005}.
Tissue specificity:		Sperm-specific (at protein level) (PubMed:15759005). Detectable on sperm surface only after the acrosome reaction (PubMed:15759005). {ECO:0000269\|PubMed:15759005}.
Domain:		The extracellular domain assumes a distinct boomerang shape when not bound to IZUMO1R/JUNO (PubMed:27309818). Interaction with IZUMO1R/JUNO triggers a conformation change, so that the IZUMO1 extracellular domain assumes an upright conformation (PubMed:27309818). {ECO:0000269\|PubMed:27309818}.
Domain:		The cytoplasmic C-terminus region is not essential for fertilization. It is however required for protein stability. {ECO:0000250\|UniProtKB:Q9D9J7}.
Ptm:		N-glycosylated. Glycosylation is not essential for fusion and for proper protein trafficking in sperm. {ECO:0000250\|UniProtKB:Q9D9J7}.
Ptm:		Phosphorylated. The cytoplasmic C-terminus is phosphorylated and undergoes phosphorylation changes during epididymal transit. {ECO:0000250\|UniProtKB:Q9D9J7}.
Miscellaneous:		Izumo is the name of a Japanese shrine to marriage. {ECO:0000305\|PubMed:15759005}.
Similarity:		Belongs to the Izumo family. {ECO:0000305}.