Ablation of Whirlin Long Isoform Disrupts the USH2 Protein Complex and Causes Vision and Hearing Loss

English version České info

Mutations in whirlin cause either Usher syndrome type II (USH2), a deafness-blindness disorder, or nonsyndromic deafness. The molecular basis for the variable disease expression is unknown. We show here that only the whirlin long isoform, distinct from a short isoform by virtue of having two N-terminal PDZ domains, is expressed in the retina. Both long and short isoforms are expressed in the inner ear. The N-terminal PDZ domains of the long whirlin isoform mediates the formation of a multi-protein complex that includes usherin and VLGR1, both of which are also implicated in USH2. We localized this USH2 protein complex to the periciliary membrane complex (PMC) in mouse photoreceptors that appears analogous to the frog periciliary ridge complex. The latter is proposed to play a role in photoreceptor protein trafficking through the connecting cilium. Mice carrying a targeted disruption near the N-terminus of whirlin manifest retinal and inner ear defects, reproducing the clinical features of human USH2 disease. This is in contrast to mice with mutations affecting the C-terminal portion of whirlin in which the phenotype is restricted to the inner ear. In mice lacking any one of the USH2 proteins, the normal localization of all USH2 proteins is disrupted, and there is evidence of protein destabilization. Taken together, our findings provide new insights into the pathogenic mechanism of Usher syndrome. First, the three USH2 proteins exist as an obligatory functional complex in vivo, and loss of one USH2 protein is functionally close to loss of all three. Second, defects in the three USH2 proteins share a common pathogenic process, i.e., disruption of the PMC. Third, whirlin mutations that ablate the N-terminal PDZ domains lead to Usher syndrome, but non-syndromic hearing loss will result if they are spared.

Vyšlo v časopise: Ablation of Whirlin Long Isoform Disrupts the USH2 Protein Complex and Causes Vision and Hearing Loss. PLoS Genet 6(5): e32767. doi:10.1371/journal.pgen.1000955
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.pgen.1000955

Souhrn

Zdroje

1. BeatyTH

BoughmanJA

1986 Problems in detecting etiological heterogeneity in genetic disease illustrated with retinitis pigmentosa. Am J Med Genet 24 493 504

2. BoughmanJA

VernonM

ShaverKA

1983 Usher syndrome: definition and estimate of prevalence from two high-risk populations. J Chronic Dis 36 595 603

3. AdatoA

VreugdeS

JoensuuT

AvidanN

HamalainenR

2002 USH3A transcripts encode clarin-1, a four-transmembrane-domain protein with a possible role in sensory synapses. Eur J Hum Genet 10 339 350

4. GellerSF

GuerinKI

ViselM

PhamA

LeeES

2009 CLRN1 is nonessential in the mouse retina but is required for cochlear hair cell development. PLoS Genet 5 doi:10.1371/journal.pgen.1000607

5. PetitC

2001 Usher syndrome: from genetics to pathogenesis. Annu Rev Genomics Hum Genet 2 271 297

6. ReinersJ

Nagel-WolfrumK

JurgensK

MarkerT

WolfrumU

2006 Molecular basis of human Usher syndrome: deciphering the meshes of the Usher protein network provides insights into the pathomechanisms of the Usher disease. Exp Eye Res 83 97 119

7. RoepmanR

WolfrumU

2007 Protein networks and complexes in photoreceptor cilia. Subcell Biochem 43 209 235

8. WilliamsDS

2008 Usher syndrome: animal models, retinal function of Usher proteins, and prospects for gene therapy. Vision Res 48 433 441

9. Hmani-AifaM

BenzinaZ

ZulfiqarF

DhouibH

ShahzadiA

2009 Identification of two new mutations in the GPR98 and the PDE6B genes segregating in a Tunisian family. Eur J Hum Genet 17 474 482

10. MburuP

MustaphaM

VarelaA

WeilD

El-AmraouiA

2003 Defects in whirlin, a PDZ domain molecule involved in stereocilia elongation, cause deafness in the whirler mouse and families with DFNB31. Nat Genet 34 421 428

11. TliliA

CharfedineI

LahmarI

BenzinaZ

MohamedBA

2005 Identification of a novel frameshift mutation in the DFNB31/WHRN gene in a Tunisian consanguineous family with hereditary non-syndromic recessive hearing loss. Hum Mutat 25 503

12. EbermannI

SchollHP

Charbel IssaP

BecirovicE

LamprechtJ

2006 A novel gene for Usher syndrome type 2: mutations in the long isoform of whirlin are associated with retinitis pigmentosa and sensorineural hearing loss. Hum Genet 121 203 211

13. BelyantsevaIA

BogerET

NazS

FrolenkovGI

SellersJR

2005 Myosin-XVa is required for tip localization of whirlin and differential elongation of hair-cell stereocilia. Nat Cell Biol 7 148 156

14. van WijkE

van der ZwaagB

PetersT

ZimmermannU

Te BrinkeH

2006 The DFNB31 gene product whirlin connects to the Usher protein network in the cochlea and retina by direct association with USH2A and VLGR1. Hum Mol Genet 15 751 765

15. ShengM

SalaC

2001 PDZ domains and the organization of supramolecular complexes. Annu Rev Neurosci 24 1 29

16. MaciasMJ

WiesnerS

SudolM

2002 WW and SH3 domains, two different scaffolds to recognize proline-rich ligands. FEBS Lett 513 30 37

17. AdatoA

LefevreG

DelpratB

MichelV

MichalskiN

2005 Usherin, the defective protein in Usher syndrome type IIA, is likely to be a component of interstereocilia ankle links in the inner ear sensory cells. Hum Mol Genet 14 3921 3932

18. EudyJD

WestonMD

YaoS

HooverDM

RehmHL

1998 Mutation of a gene encoding a protein with extracellular matrix motifs in Usher syndrome type IIa. Science 280 1753 1757

19. van WijkE

PenningsRJ

te BrinkeH

ClaassenA

YntemaHG

2004 Identification of 51 novel exons of the Usher syndrome type 2A (USH2A) gene that encode multiple conserved functional domains and that are mutated in patients with Usher syndrome type II. Am J Hum Genet 74 738 744

20. WestonMD

LuijendijkMW

HumphreyKD

MollerC

KimberlingWJ

2004 Mutations in the VLGR1 gene implicate G-protein signaling in the pathogenesis of Usher syndrome type II. Am J Hum Genet 74 357 366

21. MichalskiN

MichelV

BahloulA

LefevreG

BarralJ

2007 Molecular characterization of the ankle-link complex in cochlear hair cells and its role in the hair bundle functioning. J Neurosci 27 6478 6488

22. KerstenF

van WijkE

van ReeuwijkJ

van der ZwaagB

MaerkerT

2009 Whirlin associates with the Cav1.3 ({alpha}1D) channels in photoreceptors, defining a novel member of the Usher protein network. Invest Ophthalmol Vis Sci

23. MaerkerT

van WijkE

OverlackN

KerstenFF

McGeeJ

2008 A novel Usher protein network at the periciliary reloading point between molecular transport machineries in vertebrate photoreceptor cells. Hum Mol Genet 17 71 86

24. DelpratB

MichelV

GoodyearR

YamasakiY

MichalskiN

2005 Myosin XVa and whirlin, two deafness gene products required for hair bundle growth, are located at the stereocilia tips and interact directly. Hum Mol Genet 14 401 410

25. HongDH

PawlykB

SokolovM

StrisselKJ

YangJ

2003 RPGR isoforms in photoreceptor connecting cilia and the transitional zone of motile cilia. Invest Ophthalmol Vis Sci 44 2413 2421

26. LiuX

BulgakovOV

DarrowKN

PawlykB

AdamianM

2007 Usherin is required for maintenance of retinal photoreceptors and normal development of cochlear hair cells. Proc Natl Acad Sci U S A 104 4413 4418

27. PetersKR

PaladeGE

SchneiderBG

PapermasterDS

1983 Fine structure of a periciliary ridge complex of frog retinal rod cells revealed by ultrahigh resolution scanning electron microscopy. J Cell Biol 96 265 276

28. WatanabeN

MiyakeY

WakabayashiT

UsukuraJ

1999 Periciliary structure of developing rat photoreceptor cells. A deep etch replica and freeze substitution study. J Electron Microsc (Tokyo) 48 929 935

29. GoodyearRJ

MarcottiW

KrosCJ

RichardsonGP

2005 Development and properties of stereociliary link types in hair cells of the mouse cochlea. J Comp Neurol 485 75 85

30. McGeeJ

GoodyearRJ

McMillanDR

StaufferEA

HoltJR

2006 The very large G-protein-coupled receptor VLGR1: a component of the ankle link complex required for the normal development of auditory hair bundles. J Neurosci 26 6543 6553

31. DereticD

1998 Post-Golgi trafficking of rhodopsin in retinal photoreceptors. Eye (Lond) 12(Pt 3b) 526 530

32. PapermasterDS

2002 The birth and death of photoreceptors: the Friedenwald Lecture. Invest Ophthalmol Vis Sci 43 1300 1309

33. YangJ

LiuX

ZhaoY

AdamianM

PawlykB

2006 Subcellular localization of whirlin and its interaction with USH2A in the photoreceptors. Invest Ophthalmol Vis Sci 47 2848

34. YapCC

LiangF

YamazakiY

MutoY

KishidaH

2003 CIP98, a novel PDZ domain protein, is expressed in the central nervous system and interacts with calmodulin-dependent serine kinase. J Neurochem 85 123 134

35. WeilD

El-AmraouiA

MasmoudiS

MustaphaM

KikkawaY

2003 Usher syndrome type I G (USH1G) is caused by mutations in the gene encoding SANS, a protein that associates with the USH1C protein, harmonin. Hum Mol Genet 12 463 471

36. WolfrumU

SchmittA

2000 Rhodopsin transport in the membrane of the connecting cilium of mammalian photoreceptor cells. Cell Motil Cytoskeleton 46 95 107

37. KikkawaY

MburuP

MorseS

KominamiR

TownsendS

2005 Mutant analysis reveals whirlin as a dynamic organizer in the growing hair cell stereocilium. Hum Mol Genet 14 391 400

38. MburuP

KikkawaY

TownsendS