Biallelic loss of human CTNNA2, encoding αN-catenin, leads to ARP2/3 complex overactivity and disordered cortical neuronal migration

  • Nat Genet. 2018 Aug;50(8):1093-1101. doi: 10.1038/s41588-018-0166-0.
Ashleigh E Schaffer  1  2 Martin W Breuss  3 Ahmet Okay Caglayan  4  5 Nouriya Al-Sanaa  6 Hind Y Al-Abdulwahed  6 Hande Kaymakçalan  7 Cahide Yılmaz  8 Maha S Zaki  9 Rasim O Rosti  3 Brett Copeland  3 Seung Tae Baek  3 Damir Musaev  3 Eric C Scott  3 Tawfeg Ben-Omran  10 Ariana Kariminejad  11 Hulya Kayserili  12 Faezeh Mojahedi  13 Majdi Kara  14 Na Cai  3 Jennifer L Silhavy  3 Seham Elsharif  14 Elif Fenercioglu  15 Bruce A Barshop  16 Bulent Kara  17 Rengang Wang  3 Valentina Stanley  3 Kiely N James  3 Rahul Nachnani  3 Aneesha Kalur  18 Hisham Megahed  9 Faruk Incecik  19 Sumita Danda  20 Yasemin Alanay  21 Eissa Faqeih  22 Gia Melikishvili  23 Lobna Mansour  24 Ian Miller  25 Biayna Sukhudyan  26 Jamel Chelly  27 William B Dobyns  28 Kaya Bilguvar  4 Rami Abou Jamra  29 Murat Gunel  4 Joseph G Gleeson  30
Affiliations
  • 1. Department of Neuroscience, Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, San Diego, CA, USA. [email protected].
  • 2. Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA. [email protected].
  • 3. Department of Neuroscience, Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, San Diego, CA, USA.
  • 4. Departments of Neurosurgery, Neurobiology, and Genetics, Yale University School of Medicine, New Haven, CT, USA.
  • 5. Department of Medical Genetics, Istanbul Bilim University, Istanbul, Turkey.
  • 6. Department of Pediatrics, Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia.
  • 7. Department of Pediatrics, Istanbul Bilim University, Istanbul, Turkey.
  • 8. Department of Pediatrics, Yıldırım Beyazıt University, Ankara, Turkey.
  • 9. Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt.
  • 10. Clinical and Metabolic Genetics Section, Department of Pediatrics, Hamad Medical Corporation, Doha, Qatar.
  • 11. Kariminejad-Najmabadi Pathology and Genetic Center, Tehran, Iran.
  • 12. Department of Medical Genetics, Koç University School of Medicine, Istanbul, Turkey.
  • 13. Mashhad Medical Genetic Counseling Center, Mashhad, Iran.
  • 14. University of Tripoli, Tripoli Children's Hospital, Tripoli, Libya.
  • 15. L.E.S. Mikrogen Genetic Diseases Diagnosis Center, Istanbul, Turkey.
  • 16. Department of Pediatrics, Biochemical Genetics Program, University of California, San Diego, San Diego, CA, USA.
  • 17. Department of Pediatric Neurology, Kocaeli University, Kocaeli, Turkey.
  • 18. Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, USA.
  • 19. Department of Pediatric Neurology, Cukurova University, Adana, Turkey.
  • 20. Department of Clinical Genetics, Christian Medical College and Hospital, Vellore, India.
  • 21. Pediatric Genetics Unit, Department of Pediatrics, Acibadem Mehmet Ali Aydinlar University, Istanbul, Turkey.
  • 22. Section of Medical Genetics, Department of Pediatrics, King Fahad Medical City, Children's Hospital, Riyadh, Saudi Arabia.
  • 23. Department of Pediatrics, MediClubGeorgia, Tbilisi, Georgia.
  • 24. Pediatric Department, Neuropediatric Unit, Cairo University Children's Hospital, Cairo, Egypt.
  • 25. Neurology Department, Nicklaus Children's Hospital, Miami, FL, USA.
  • 26. Arabkir Joint Medical Center and Institute of Child and Adolescent Health, Yerevan, Armenia.
  • 27. Institut Cochin, Université Paris-Descartes, CNRS (UMR 8104), Paris, France.
  • 28. Departments of Pediatrics and Neurology, University of Washington, Seattle, WA, USA.
  • 29. Institute of Human Genetics, University of Leipzig Hospitals and Clinics, Leipzig, Germany.
  • 30. Department of Neuroscience, Rady Children's Institute for Genomic Medicine, Howard Hughes Medical Institute, University of California, San Diego, San Diego, CA, USA. [email protected].
Abstract

Neuronal migration defects, including pachygyria, are among the most severe developmental brain defects in humans. Here, we identify biallelic truncating mutations in CTNNA2, encoding αN-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 αN-catenin paralog, αE-catenin, acts as a switch regulating the balance between β-catenin and Arp2/3 actin filament activities1. Loss of αN-catenin did not affect β-catenin signaling, but recombinant αN-catenin interacted with purified actin and repressed ARP2/3 actin-branching activity. The actin-binding domain of αN-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.