A child with an inherited 0.31 Mb microdeletion of chromosome 14q32.33: Further delineation of a critical region for the 14q32 deletion syndrome
AMERICAN JOURNAL OF MEDICAL GENETICS PART A
Authors: Holder, J. Lloyd, Jr.; Lotze, Timothy E.; Bacino, Carlos; Cheung, Sau-Wai
Abstract
Chromosome 14q32.3 deletions are uncommon, with most described patients harboring a ring chromosome 14. Only 15 deletions have been described not associated with ring formation or other complex chromosomal rearrangements. Here, we describe a child with the smallest deletion of chromosome 14q32.3 reported in the literature. This child's deletion encompasses at most 0.305?Mb and six genes including NUDT14, BRF1, BTBD6, PACS2, MTA1, and TEX22. He has similar clinical findings, including mild facial dysmorphisms and intellectual disability, as other individuals with much larger deletions of the terminus of the long arm of chromosome 14. This suggests that the genes deleted in our patient contribute to the 14q32 deletion syndrome. (C) 2012 Wiley Periodicals, Inc.
The sorting protein PACS-2 promotes ErbB signalling by regulating recycling of the metalloproteinase ADAM17
NATURE COMMUNICATIONS
Authors: Dombernowsky, Sarah Louise; Samsoe-Petersen, Jacob; Petersen, Camilla Hansson; Instrell, Rachael; Hedegaard, Anne-Mette Bornhardt; Thomas, Laurel; Atkins, Katelyn Mae; Auclair, Sylvain; Albrechtsen, Reidar; Mygind, Kasper Johansen; Frohlich, Camilla; Howell, Michael; Parker, Peter; Thomas, Gary; Kveiborg, Marie
Abstract
The metalloproteinase ADAM17 activates ErbB signalling by releasing ligands from the cell surface, a key step underlying epithelial development, growth and tumour progression. However, mechanisms acutely controlling ADAM17 cell-surface availability to modulate the extent of ErbB ligand release are poorly understood. Here, through a functional genome-wide siRNA screen, we identify the sorting protein PACS-2 as a regulator of ADAM17 trafficking and ErbB signalling. PACS-2 loss reduces ADAM17 cell-surface levels and ADAM17-dependent ErbB ligand shedding, without apparent effects on related proteases. PACS-2 co-localizes with ADAM17 on early endosomes and PACS-2 knockdown decreases the recycling and stability of internalized ADAM17. Hence, PACS-2 sustains ADAM17 cell-surface activity by diverting ADAM17 away from degradative pathways. Interestingly, Pacs2-deficient mice display significantly reduced levels of phosphorylated EGFR and intestinal proliferation. We suggest that this mechanism controlling ADAM17 cell-surface availability and EGFR signalling may play a role in intestinal homeostasis, with potential implications for cancer biology.