Browsing by Author "Kariminejad, Ariana"

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    Biallelic loss of human CTNNA2, encoding alpha N-catenin, leads to ARP2/3 complex overactivity and disordered cortical neuronal migration
    (NATURE PUBLISHING GROUP, 2018-01-01) Schaffer, Ashleigh E.; Breuss, Martin W.; Caglayan, Ahmet Okay; Al-Sanaa, Nouriya; Al-Abdulwahed, Hind Y.; Kaymakcalan, Hande; Yilmaz, Cahide; Zaki, Maha S.; Rosti, Rasim O.; Copeland, Brett; Baek, Seung Tae; Musaev, Damir; Scott, Eric C.; Ben-Omran, Tawfeg; Kariminejad, Ariana; Kayserili, Hulya; Mojahedi, Faezeh; Kara, Majdi; Cai, Na; Silhavy, Jennifer L.; Elsharif, Seham; Fenercioglu, Elif; Barshop, Bruce A.; Kara, Bulent; Wang, Rengang; Stanley, Valentina; James, Kiely N.; Nachnani, Rahul; Kalur, Aneesha; Megahed, Hisham; Incecik, Faruk; Danda, Sumita; Alanay, Yasemin; Faqeih, Eissa; Melikishvili, Gia; Mansour, Lobna; Miller, Ian; Sukhudyan, Biayna; Chelly, Jamel; Dobyns, William B.; Bilguvar, Kaya; Abou Jamra, Rami; Gunel, Murat; Gleeson, Joseph G.
    Neuronal migration defects, including pachygyria, are among the most severe developmental brain defects in humans. Here, we identify biallelic truncating mutations in CTNNA2, encoding alpha N-catenin, in patients with a distinct recessive form of pachygyria. CTNNA2 was expressed in human cerebral cortex, and its loss in neurons led to defects in neurite stability and migration. The alpha N-catenin paralog, alpha E-catenin, acts as a switch regulating the balance between beta-catenin and Arp2/3 actin filament activities(1). Loss of alpha N-catenin did not affect beta-catenin signaling, but recombinant alpha N-catenin interacted with purified actin and repressed ARP2/3 actin-branching activity. The actin-binding domain of alpha N-catenin or ARP2/3 inhibitors rescued the neuronal phenotype associated with CTNNA2 loss, suggesting ARP2/3 de-repression as a potential disease mechanism. Our findings identify CTNNA2 as the first catenin family member with biallelic mutations in humans, causing a new pachygyria syndrome linked to actin regulation, and uncover a key factor involved in ARP2/3 repression in neurons.
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    Mutations in ATP6V1E1 or ATP6V1A Cause Autosomal-Recessive Cutis Laxa
    (CELL PRESS, 2017-01-01) Van Damme, Tim; Gardeitchik, Thatjana; Mohamed, Miski; Guerrero-Castillo, Sergio; Freisinger, Peter; Guillemyn, Brecht; Kariminejad, Ariana; Dalloyaux, Daisy; Van Kraaij, Sanne; Lefeber, Dirk J.; Syx, Delfien; Steyaert, Wouter; De Rycke, Riet; Hoischen, Alexander; Kamsteeg, Erik-Jan; Wong, Sunnie Y.; van Scherpenzeel, Monique; Jamali, Payman; Brandt, Ulrich; Nijtmans, Leo; Korenke, G. Christoph; Chung, Brian H. Y.; Mak, Christopher C. Y.; Hausser, Ingrid; Kornak, Uwe; Fischer-Zirnsak, Bjorn; Strom, Tim M.; Meitinger, Thomas; Alanay, Yasemin; Utine, Gulen E.; Leung, Peter K. C.; Ghaderi-Sohi, Siavash; Coucke, Paul; Symoens, Sofie; De Paepe, Anne; Thiel, Christian; Haack, Tobias B.; Malfait, Fransiska; Morava, Eva; Callewaert, Bert; Wevers, Ron A.
    Defects of the V-type proton (H+) ATPase (V-ATPase) impair acidification and intracellular trafficking of membrane-enclosed compartments, including secretory granules, endosomes, and lysosomes. Whole-exome sequencing in five families affected by mild to severe cutis laxa, dysmorphic facial features, and cardiopulmonary involvement identified biallelic missense mutations in ATP6V1E1 and ATP6V1A, which encode the El and A subunits, respectively, of the V-1 domain of the heteromultimeric V-ATPase complex. Structural modeling indicated that all substitutions affect critical residues and inter- or intrasubunit interactions. Furthermore, complexome profiling, a method combining blue-native gel electrophoresis and liquid chromatography tandem mass spectrometry, showed that they disturb either the assembly or the stability of the V-ATPase complex. Protein glycosylation was variably affected. Abnormal vesicular trafficking was evidenced by delayed retrograde transport after brefeldin A treatment and abnormal swelling and fragmentation of the Golgi apparatus. In addition to showing reduced and fragmented elastic fibers, the histopathological hallmark of cutis laxa, transmission electron microscopy of the dermis also showed pronounced changes in the structure and organization of the collagen fibers. Our findings expand the clinical and molecular spectrum of metabolic cutis laxa syndromes and further link defective extracellular matrix assembly to faulty protein processing and cellular trafficking caused by genetic defects in the V-ATPase complex.