Protein: Reticulocyte-binding protein homolog 2b (PfR2Hb) (PfRH2b) [Cleaved into: Reticulocyte-binding protein homolog 2b 85 kDa form; Reticulocyte-binding protein homolog 2b 297 kDa form] (C0H5F4)
Organism: Plasmodium falciparum (isolate 3D7)
Function: During the asexual blood stage, binds to a chymotrypsin sensitive, neuraminidase and trypsin resistant receptor on the surface of the host erythrocyte and thus is involved in merozoite invasion. The various processed forms have different binding affinities for the erythrocyte receptor; full length form binds with higher affinity followed by the 250 kDa form and finally the 300 kDa form while the 160 kDa form does not bind erythrocytes. After merozoite attachment and reorientation, RH2b binding to its erythrocyte receptor triggers an increase in intracellular Ca(2+) within the parasite resulting in the release of microneme proteins such as EBA175 which in turn leads to the formation of the tight junction between parasite and host cell.
Subcellular location: Cell membrane {ECO:0000269|PubMed:27438226}; Single-pass type I membrane protein {ECO:0000305}. Cytoplasmic vesicle, secretory vesicle, rhoptry {ECO:0000269|PubMed:12228308, ECO:0000269|PubMed:27438226}. Cell junction, tight junction {ECO:0000269|PubMed:27438226}. Secreted {ECO:0000269|PubMed:27438226}. Note=Localizes to the rhoptry neck at the apical end of the merozoite (PubMed:12228308, PubMed:27438226). During merozoite invasion, mainly localizes to the tight junction formed between the parasite and the host erythrocyte membranes and then moves with the tight junction to the posterior end as the parasite enters the erythrocyte (PubMed:27438226). Also, the different processed forms are released from the membrane following proteolytic cleavage (PubMed:27438226). The remaining 7 kDa processed transmembrane fragment is incorporated into the newly formed ring stage (PubMed:21698217). {ECO:0000269|PubMed:12228308, ECO:0000269|PubMed:21698217, ECO:0000269|PubMed:27438226}.; SUBCELLULAR LOCATION: [Reticulocyte-binding protein homolog 2b 85 kDa form]: Secreted {ECO:0000269|PubMed:21698217}. Cell membrane {ECO:0000269|PubMed:21698217}; Peripheral membrane protein {ECO:0000269|PubMed:21698217}; Extracellular side {ECO:0000269|PubMed:21698217}. Note=In mature schizont, co-localizes to the apical end of the schizont and the merozoite with reticulocyte-binding protein homolog 2b 297 kDa form. During merozoite invasion, shed from the cell surface. {ECO:0000269|PubMed:21698217}.; SUBCELLULAR LOCATION: [Reticulocyte-binding protein homolog 2b 297 kDa form]: Secreted {ECO:0000269|PubMed:21698217}. Cell membrane {ECO:0000269|PubMed:21698217}; Single-pass type I membrane protein {ECO:0000305}. Note=In mature schizont, co-localizes to the apical end of the schizont and the merozoite with reticulocyte-binding protein homolog 2b 85 kDa form. During merozoite invasion, shed from the cell surface. {ECO:0000269|PubMed:21698217}.
Interaction partners:
- ATP synthase subunit beta
- Aurora kinase
- Serine/threonine protein kinase, putative
- Aurora kinase
- Serine/threonine protein kinase, putative
- JmjC domain-containing protein, putative
- Rh5-interacting protein
- Reticulocyte-binding protein homolog 1
- Reticulocyte-binding protein homolog 5
- Kinesin-5
Sequence:
MKTTLFCSISFCNIIFFFLELSHEHFVGQSSNTHGASSVTDFNFSEEKNLKSFEGKNNNNDNYASINRLYRKKPYMKRSLINLENDLFRLEPISYIQRYYKKNINRSDIFHNKKERGSKVYSNVSSFHSFIQEGKEEVEVFSIWGSNSVLDHIDVLRDNGTVVFSVQPYYLDIYTCKEAILFTTSFYKDLDKSSITKINEDIEKFNEEIIKNEEQCLVGGKTDFDNLLIVLENAEKANVRKTLFDNTFNDYKNKKSSFYNCLKNKKNDYDKKIKNIKNEITKLLKNIESTGNMCKTESYVMNNNLYLLRVNEVKSTPIDLYLNRAKELLESSSKLVNPIKMKLGDNKNMYSIGYIHDEIKDIIKRYNFHLKHIEKGKEYIKRITQANNIADKMKKDELIKKIFESSKHFASFKYSNEMISKLDSLFIKNEEILNNLFNNIFNIFKKKYETYVDMKTIESKYTTVMTLSEHLLEYAMDVLKANPQKPIDPKANLDSEVVKLQIKINEKSNELDNAISQVKTLIIIMKSFYDIIISEKASMDEMEKKELSLNNYIEKTDYILQTYNIFKSKSNIINNNSKNISSKYITIEGLKNDIDELNSLISYFKDSQETLIKDDELKKNMKTDYLNNVKYIEENVTHINEIILLKDSITQRIADIDELNSLNLININDFINEKNISQEKVSYNLNKLYKGSFEELESELSHFLDTKYLFHEKKSVNELQTILNTSNNECAKLNFMKSDNNNNNNNSNIINLLKTELSHLLSLKENIIKKLLNHIEQNIQNSSNKYTITYTDINNRMEDYKEEIESLEVYKHTIGNIQKEYILHLYENDKNALAVHNTSMQILQYKDAIQNIKNKISDDIKILKKYKEMNQDLLNYYEILDKKLKDNTYIKEMHTASLVQITQYIPYEDKTISELEQEFNNNNQKLDNILQDINAMNLNINILQTLNIGINACNTNNKNVEHLLNKKIELKNILNDQMKIIKNDDIIQDNEKENFSNVLKKEEEKLEKELDDIKFNNLKMDIHKLLNSYDHTKQNIESNLKINLDSFEKEKDSWVHFKSTIDSLYVEYNICNQKTHNTIKQQKNDIIELIYKRIKDINQEIIEKVDNYYSLSDKALTKLKSIHFNIDKEKYKNPKSQENIKLLEDRVMILEKKIKEDKDALIQIKNLSHDHFVNADNEKKKQKEKEEDDEQTHYSKKRKVMGDIYKDIKKNLDELNNKNLIDITLNEANKIESEYEKILIDDICEQITNEAKKSDTIKEKIESYKKDIDYVDVDVSKTRNDHHLNGDKIHDSFFYEDTLNYKAYFDKLKDLYENINKLTNESNGLKSDAHNNNTQVDKLKEINLQVFSNLGNIIKYVEKLENTLHELKDMYEFLETIDINKILKSIHNSMKKSEEYSNETKKIFEQSVNITNQFIEDVEILKTSINPNYESLNDDQIDDNIKSLVLKKEEISEKRKQVNKYITDIESNKEQSDLHLRYASRSIYVIDLFIKHEIINPSDGKNFDIIKVKEMINKTKQVSNEAMEYANKMDEKNKDIIKIENELYNLINNNIRSLKGVKYEKVRKQARNAIDDINNIHSNIKTILTKSKERLDEIKKQPNIKREGDVLNNDKTKIAYITIQINNGRIESNLLNILNMKHNIDTILNKAMDYMNDVSKSDQIVINIDSLNMNDIYNKDKDLLINILKEKQNMEAEYKKMNEMYNYVNETEKEIIKHKKNYEIRIMEHIKKETNEKKKKFMESNNKSLTTLMDSFRSMFYNEYINDYNINENFEKHQNILNEIYNGFNESYNIINTKMTEIINDNLDYNEIKEIKEVAQTEYDKLNKKVDELKNYLNNIKEQEGHRLIDYIKEKIFNLYIKCSEQQNIIDDSYNYITVKKQYIKTIEDVKFLLDSLNTIEEKNKSVANLEICTNKEDIKNLLKHVIKLANFSGIIVMSDTNTEITPENPLEDNDLLNLQLYFERKHEITSTLENDSDLELDHLGSNSDESIDNLKVYNDIIELHTYSTQILKYLDNIQKLKGDCNDLVKDCKELRELSTALYDLKIQITSVINRENDISNNIDIVSNKLNEIDAIQYNFEKYKEIFDNVEEYKTLDDTKNAYIVKKAEILKNVDINKTKEDLDIYFNDLDELEKSLTLSSNEMEIKTIVQNSYNSFSDINKNINDIDKEMKTLIPMLDELLNEGHNIDISLYNFIIRNIQIKIGNDIKNIREQENDTNICFEYIQNNYNFIKSDISIFNKYDDHIKVDNYISNNIDVVNKHNSLLSEHVINATNIIENIMTSIVEINEDTEMNSLEETQDKLLELYENFKKEKNIINNNYKIVHFNKLKEIENSLETYNSISTNFNKINETQNIDILKNEFNNIKTKINDKVKELVHVDSTLTLESIQTFNNLYGDLMSNIQDVYKYEDINNVELKKVKLYIENITNLLGRINTFIKELDKYQDENNGIDKYIEINKENNSYIIKLKEKANNLKENFSKLLQNIKRNETELYNINNIKDDIMNTGKSVNNIKQKFSSNLPLKEKLFQMEEMLLNINNIMNETKRISNTDAYTNITLQDIENNKNKENNNMNIETIDKLIDHIKIHNEKIQAEILIIDDAKRKVKEITDNINKAFNEITENYNNENNGVIKSAKNIVDKATYLNNELDKFLLKLNELLSHNNNDIKDLGDEKLILKEEEERKERERLEKAKQEEERKERERIEKEKQEKERLEREKQEQLKKEALKKQEQERQEQQQKEEALKRQEQERLQKEEELKRQEQERLEREKQEQLQKEEELRKKEQEKQQQRNIQELEEQKKPEIINEALVKGDKILEGSDQRNMELSKPNVSMDNTNNSPISNSEITESDDIDNSENIHTSHMSDIESTQTSHRSNTHGQQISDIVEDQITHPSNIGGEKITHNDEISITGERNNISDVNDYSESSNIFENGDSTINTSTRNTSSTHDESHISPISNAYDHVVSDNKKSMDENIKDKLKIDESITTDEQIRLDDNSNIVRIDSTDQRDASSHGSSNRDDDEISHVGSDIHMDSVDIHDSIDTDENADHRHNVNSVDSLSSSDYTDTQKDFSSIIKDGGNKEGHAENESKEYESQTEQTHEEGIMNPNKYSISEVDGIKLNEEAKHKITEKLVDIYPSTYRTLDEPMETHGPNEKFHMFGSPYVTEEDYTEKHDYDKHEDFNNERYSNHNKMDDFVYNAGGVVCCVLFFASITFFSMDRSNKDECDFDMCEEVNNNDHLSNYADKEEIIEIVFDENEEKYF