475
146316470016778155
Reham80810820234159267415553730
Mahmoud1596108202341773144626398029521121
Moh’d277510820234177340488521690
Milhem352310820234177229337485594771
Department8081296014981156232313348384495569643679
of15241296014975112
Pathology16721296014959130166235310330405486546
College8081440014989164183203277358433
of12781440014975111
Medicine142614400149110184264284353373446521
and19831440014981155236
Health22551440014974148229248285354
Sciences26461440014954123142217290359433478
Dissertation8071865017098132193255344389431524566599689773
Title80720590122426696120184
ELUCIDATION1717205701294991151203228290346386412477542
OF22842057012965111
THE24182057012951114163
CELLULAR26062057012952101143185245287345399
AND30312057012957122183
MOLECULAR32402057012985151193241292356398456511
MECHANISMS37762057012985134185247305370395440526571
OF43722057012966111
MISSENSE45092057012985111156201250314360408
MUTATIONS49432057012985149198249289314380444489
ASSOCIATED54582057012958103148213266291349389438500
WITH59832057012989114163225
FAMILIAL6231205701294910117172177012986111153178236278
EXUDATIVE20172177012953105169231287327353409458
VITREORETINOPATHY2502217701295682130185233297352400449474539604656707748810859
AND33872177012958123184
CONGENITAL35942177012956120185248297361386435486528
MYASTHEN-IC41482177012986134185230278340389454484510562
SYNDROME4732217701294997161223277342427476
Faculty8072334012248114178238262292350
Advisor11852334012274140196220264328360
Prof.1717233601205989154186213
Bassam19582336012058126165203272366
Ali2351233601207494114
Defense8072489012270134162226286330394
Date12292489012270136166230
2217172491012055111
February18552491012049114182212273341371425
201523082491012055111166221
Abstract8072804012274140184214246312376406
The171728110963483135
endoplasmic1872281109652101156208263279333364440456507
reticulum240228110962274101117168217233282357
(ER),278128110962871119149171
within297228110966783110159175223
eukaryotic3216281109652100141195219262315342358409
cells,3646281109652104120136167189
is385728110961445
a3923281109654
hub399828110964997152
for417228110962376100
protein429228110965579131158210226275
folding45892811096237692147163211265
and4875281109654103158
assembly.505328110965586117169244299315357380
Mis-folded545328110967490121147172225241295347402
proteins587628110965478130158210226274305
and6202281109654103158
unassembled171729070964997152183214266341396412464519
subunits225829070964088143192240256283315
of259529070966186
protein270329070966488140167219235284
complexes3009290709661113188243259311349401432
are346329070966488140
retained362529070963384112166182231283338
in398529070962574
the408129070963685137
ER4240290709652100
and4362290709664113168
degraded4552290709663115169193248303355410
by4984290709663106
a5112290709664
process519829070966488140191243274306
termed552629070963688112189241296
endoplasmic5844290709661110165217272288342373448464516
reticulum171730030962476103119171219235284359
associated210130030965586117170221237292319371426
degradation2553300309654106160184239294348375391444493
(ERAD).306830030963376124183243272295
Frizzled33853003096426682116150166218273
class368330030965268123154185
receptor389030030962779131183237265317341
44253300309648
(FZD4)432330030963372110170214243
and4592300309655103158
muscle,4776300309675124155206222274296
skeletal,509530030963474126142194221276292314
receptor543130030962879131183238265317341
tyrosine57953003096307397149180196245297
kinase611430030964460108163194246
(MuSK)1717309909630103152192239268
are200730990966791143
Wnt2184309909677125153
receptors.235930990963687139191246273325349380402
These278430990964594146177229
proteins303530990966791143170222238287318
contain3375309909664116165192247263312
the370930990963988140
cyste-ine-rich3871309909663106137164216243259308360386410426478527
domain4420309909667119194249265314
(Fz-CRD)475630990964180114141206254314343
required512130990963688143191207231283338
for548130990963789113
dimerization561730990966682157209233249283338365381433482
in612130990962877
the622030990963988140
ER.171731950964391114
Mutations1863319509673122149204231247299348379
in226431950962675
FZD4236131950964988147191
and2575319509664113168
MuSK2775319509674122162210
genes3007319509664116164216247
are327731950966488140
known343931950965099152218267
to372831950963790
cause3840319509662116165196248
familial411031950963590165181197213268284
exudative4416319509662100149204259286302346398
vitreoretinopathy48363195096557198122173226250302329345393446500555582631674
(FEVR,553231950964078121177226248
an5802319509665114
autosomal5938319509665113141193224276351406422
dominant1717329109655107182198247302350378
disease)211732910966278109161216247299328
and2467329109662111166
congeni-tal2655329109659112160214266315331358385439455
myasthenic3140329109675118172203231279331380396448
syndrome361032910963981130185209261336388
(CMS,4020329109637102176216238
an4280329109662111
autosomal4413329109662111138190221274349403419
recessive485432910963283135187218249265310362
disease),523832910966278109161216247299328350
respectively.561132910963183114168220272299315360412428470493
It612632910962552
was6208329109666121152
hypothesized171733870964992146199226275327358374408460514
that225433870963281135162
missense244433870967591122153205254285337
mutations2808338709675124151205232248301350381
within321633870966682110158174223
Fz-CRD346133870964478105170218278
lead376133870962173128183
to396633870963284
misfolding407833870967591122147199215270286335389
of448933870965783
FZD4459433870964482142186
and4807338709655104158
MuSK4993338709673122162209
proteins522933870965579131158210226275306
and5562338709655104158
consequent5743338709656109158189241295344396445472
ERretention.623733870964896171734830962476103155204231247299348370
Investigating210934830961362106158189217233286341368384433487
the261834830962271123
molecular2758348309675128144196247296312367391
mechanism3166348309675127179227282331347378453
of363634830965378
these373634830962271123154206
mutations3959348309675124151205232248301350381
is436234830961142
important442634830961186141193217244299348375
since48233483096264291143195
misfolded503534830967591122147199215270322377
protein542934830965579131158210226275
and5721348309655103158
ER-targeted589634830964392118146200224278330357409464
therapies171735790962776128152207261277329360
are210435790965579130
in225735790962069
development.2353357909655107151203219272326401453502529551
Wild-type293135790967793109164191218261315367
and3325357909655104158
mutants3510357909675124151206254282313
of384535790965782
FZD4394935790964482142186
and4162357909654103158
MuSK4347357909673122162209
were4583357909666118143194
expressed479935790965795150174226257288340395
at522135790965481
37532435790964994
°C5440357909637102
in556435790962169
HeLa,5660357909655107144198221
COS-7,5907357909665135175201246268
and6202357909654103158
HEK293171736750965598145189233278
cells2017367509667119135151182
and2221367509669118173
their241636750964291143159183
subcellular262136750964695149201253269285334350404428
localizations307236750963083135189205221255310337353405454485
were3579367509682134158209
investigated381136750963079124176207234250304358385437492
by4325367509670113
confocal4460367509666119168193245297352368
microscopy486436750967692143167219250302355409452
imaging5338367509631106161215231279333
and5693367509670119174
glycosidase588936750966884127179231262278333388419471
treatments.171737710962751103157185260312360388419441
Abnormal2185377109659114163215239316371387
trafficking259437710963257111136156175227267283332386
was3007377109667121152
demonstrated3187377109655107182234283314341365420447499554
in376337710962170
10385537710964994
of397137710965783
21407637710964994
stud-ied419237710963663112167193209261316
mutants;4535377109675124151206254282313335
nine489237710965470119171
mutants5090377109675124151206254281312
were5430377109666118142194
within565137710966783110159175224
Fz-CRD589737710964478104169218277
and6197377109659108163
one1717386709652101153
was1892386709680135166
distant208038670966884115142197246273
from237538670963862114189
Fz-CRD.258738670965286112177226285307
These291738670964796148179231
ER-retained3170386709656105131155207234289305353405460
mu-tants3666386709675123150177232280308339
were4027386709679131156207
improperly4256386709630105159183235290342366382425
N-glycosylated470338670967299153169212264316347390406460488540594
confirming5320386709665117166185205229306322371425
ER-localization.5767386709656105131147199251306322338372427454470522571593
They171739630963483135178
were1915396309667119143195
tagged213239630962680134188240295
with244739630966783110159
polyubiquitin2626396309655107123166215270286340389405432448497
chains3143396309652101156172220251
confirming3415396309652104153173192216293309358412
targeting384939630962681105158210238254302356
for422739630962476101
proteasomal434839630965579131158210265296348423478494
degradation.4863396309654106160184239294348375391444493515
The540039630963381133
half-lives5554396309649104120145171187203248300331
of590539630965378
wild-type60043963096668298153179207249304356
MuSK1717405909674122162209
and1947405909655103158
P344R-MuSK212640590964792136180229255329377417465
were2611405909667119143195
90282640590964489
and2936405909654103158
37311440590964589
min,322440590967591140162
respectively;340840590962374105160212264291307351403419462484
the391440590962675127
latter40634059096146996123175199
half-life4283405909649103119145171187203228280
improved458540590961590145169221265317372
on4978405909652101
incubation510140590961463115164218273300316368417
with553940590966682109158
the571940590962675127
proteasomal586640590965579131158210265296348423478494
inhibitor171741550961665114130184200227280304
MG132.2040415509673143187232276298
The236041550963180132
P344R-MuSK251141550964791136180229255329377417464
kinase299441550964157105160191243
mutant3256415509675124151205254281
showed356041550962776128195247302
around388141550965478130179228283
50%418341550964488150
of435241550965378
its44524155096134071
in454541550961361
vivo462541550964561105157
autophosphoryla-tion4801415509655104131183238287339370425473526550593609663690717733785834
activity.5654415509655106134150194210237280302
Trafficking597841550963153107133152172223263279328382
defects1717425109655107132184236263294
in203342510961159
three21154251096217094146198
of232942510965378
the242942510962271123
10256842510964589
mutants2674425109675123151205254281312
(M105T-FZD4,300842510962498142187231265292330369428473495
C204Y-FZD4,3519425109666110154198246272311350409453476
and4011425109655104159
P344R-MuSK)418642510964892136181229256329378418465495
were4697425109667119143195
rescued491442510961870101153201253308
by523942510965597
expression535342510965291145169221252283299351400
at577042510965582
27586842510964589
°C597942510962792
and6088425109654103158
by626342510965497
chemical1717434709652101153228244295350366
chaperones2106434709652101155210262286338387439470
(2.5-7.5%25984347096307597141168212234278340
glycerol,296143470965470113165217241293309331
0.1-1%331443470964568112139183245
dime-thyl358243470965571146198224251300343359
sulfoxide,39634347096328197122174213229283335358
10434343470964589
μM4455434709646120
thapsigargin,459743470962877131186217233287341366419435484506
or512643470965377
15225434709645
μM5293434709646120
curcumin).5436434709652100124175224299315364393416
Trafficking587443470963556111136156175227267283332386
of628343470965277
wild-type17174443096668298153180207250304356
FZD4209244430963977137181
was2292444309667121152
not2463444309649101128
affected261044430965580105157209236288343
by297244430965497
co-expression3088444309652104131183221276300352383414430482531
with363844430966682109158
any3815444309655103146
of398044430965378
the408044430962472124
nine422344430964965114166
ER-retained440844430964291118142193220275291340392447
mutants,4874444309675123150205254281312334
suggesting523044430962877130184236267294310359413
haploinsufficiency5662444309649103158174226242291322371396415435487503555603655698
as171745390965586
the182545390963382134
mechanism1987453909675127179228282331347378453
of246245390965984
disease.256845390966177108160215246298320
Thus,291045390964089138169191
all31234539096617793
nine323845390965571119171
studied343245390963764112167183235290
Fz-CRD374445390964579106171219279
mutants4051453909675124151205254281312
of438645390965883
FEVR449145390964588144193
and4706453909661109164
CMS4898453909665139179
resulted509945390963082113161177205257311
in543345390962270
misfolded553245390967591122147199215270322377
proteins.593145390966185137164216232281312334
In628745390962473
contrast,1717463509652104153180204259290317339
only2078463509663112128171
one2271463509663112164
of245746350966388
the256846350963786138
122728463509655100
mutants2861463509675123150205254281312
outside3195463509663112139170186241293
Fz-CRD351046350964983110175224283
resulted381546350963587118166182210262316
in415446350962675
ER-retention.4251463509654102129153205232284333360376428477499
These477246350964594146177229
findings50234635096305098153169218272303
demon-strate5348463509666118193245294320351378403457484536
a5906463509666
common5994463509662115190265317366
mechanism1717473109675127179228282331347378453
for219247310963385109
diseases232347310966379110162216247299330
associated267647310966293124176228244299326378433
with313847310966783110159
Fz-CRD331947310964680107172220280
missense362847310967591122153205254285337
mutations.3995473109675124151205232248301350381403
Disorders442747310966076107159183238290314345
of479447310966085
Fz-CRD490147310964680107172221280
could5203473109659112161177231
be5456473109662114
amenable5593473109662137189238292347363415
to603047310963587
novel6139473109656109153205221
therapies171748270962776128152207261277329360
that209948270963382137164
alleviate22854827096607692144188204259286338
protein264548270966185137164216232281
misfolding.295348270967692123148200216271287336390412
Research7635105017081171232322414459549633
Relevance14355105017081171204294372465549638728
and22025105017093177269
Potential25105105017079168210300384426459552585
Impact31355105017039170263355445487
Reham763535909649101149204279
Milhem’s107053590967389105154206281309340
PhD1432535909653102162
research161653590962981112164219243294343
resulted198153590963081112161177204256311
in231453590962170
the240653590963382134
elucidation256253590965874122174190245299326342395444
of302853590965883
the313353590963381133
cellular3289535909657109125141190206260284
mechanisms3601535909675127179228282331347378453484
underlying4107535909654103158210234250293309358412
many4546535909675130179222
mutations4795535909675124151206233249301350381
causing5198535909658112161192208257311
two553153590963299151
ge-netic5704535909660112138187239266282334
disorders,606053590966076107160184238290314345368
namely763545509649103178230246289
congenital1076545509651104153206258307323350405421
myasthenic1520545509675118173204231280332380396448
syndrome199054550963275124179203255330382
and2395545509655104159
familial257654550962681156172188204258274
exudative287354550965291140194249276292336388
vitreoretinopathy.32845455096456188112164216240292319335384436491545573621664686
These399354550963583135167219
findings42345455096204088143159208262293
are455054550965579131
original47045455096527692146162211266282
and5009545509654103158
are519054550965579131
likely53435455096173373125141184
to554954550962881
have5653545509649103148200
impact587554550961792146201253280
on6178545509652101
our6302545509653101126
understanding76355510964997152204228259286341390445461510563
of134755510965378
the144755510962675127
parthenogenesis1594555109655110134161210262310363417469517569600616647
of226255510965378
these236255510962675127158210
incurable259455510961563115164188243297313365
disorders298055510965571102154178233285309340
and3341555109654103158
possibly3520555109654107138169185239255298
help3839555109649101117172
in403355510961463
develop-ing4117555109655107151203219272326353369418471
novel4609555109649102146198214
therapies484555510962675127151205260276328359
for522655510962476101
them.534955510962574126201223
The559555510963281133
results575055510962375106155171198229
have6000555109648103147199
been6220555109655107159208
published763564709655103158174190221270322376
in116256470961766
journals125056470961770118142193248264295
that156756470962877132159
are174956470965579131
in190256470961766
the199056470962877129
top214156470962981136
5-10%229956470964572116161223
of254556470965278
their264556470962877129145169
respective283656470962577108163215266294310354406
fields.32645647096214092108163194216