title: Identification and functional characterization of three NoLS (nucleolar localisation signals) mutations of the CDC73 gene.
abstract: Hyperparathyroidism Jaw-Tumour Syndrome (HPT-JT) is characterized by primary hyperparathyroidism (PHPT), maxillary/mandible ossifying fibromas and by parathyroid carcinoma in 15% of cases. Inactivating mutations of the tumour suppressor CDC73/HRPT2 gene have been found in HPT-JT patients and also as genetic determinants of sporadic parathyroid carcinoma/atypical adenomas and, rarely, typical adenomas, in familial PHPT. Here we report the genetic and molecular analysis of the CDC73/HRPT2 gene in three patients affected by PHPT due to atypical and typical parathyroid adenomas, in one case belonging to familial PHPT. Flag-tagged WT and mutant CDC73/HRPT2 proteins were transiently transfected in HEK293 cells and functional assays were performed in order to investigate the effect of the variants on the whole protein expression, nuclear localization and cell overgrowth induction. We identified four CDC73/HRPT2 gene mutations, three germline (c.679_680delAG, p.Val85_Val86del and p.Glu81_Pro84del), one somatic (p.Arg77Pro). In three cases the mutation was located within the Nucleolar Localisation Signals (NoLS). The three NoLS variants led to instability either of the corresponding mutated protein or mRNA or both. When transfected in HEK293 cells, NoLS mutated proteins mislocalized with a predeliction for cytoplasmic or nucleo-cytoplasmic localization and, finally, they resulted in overgrowth, consistent with a dominant negative interfering effect in the presence of the endogenous protein.
authors: Gastroenterology, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo (FG), Italy.
authors: Valerio
authors: V
authors: Pazienza
authors: Annamaria
authors: A
authors: la Torre
authors: Filomena
authors: F
authors: Baorda
authors: Michela
authors: M
authors: Alfarano
authors: Massimiliano
authors: M
authors: Chetta
authors: Lucia Anna
authors: LA
authors: Muscarella
authors: Claudia
authors: C
authors: Battista
authors: Massimiliano
authors: M
authors: Copetti
authors: Dieter
authors: D
authors: Kotzot
authors: Klaus
authors: K
authors: Kapelari
authors: Dalia
authors: D
authors: Al-Abdulrazzaq
authors: Kusiel
authors: K
authors: Perlman
authors: Etienne
authors: E
authors: Sochett
authors: David E C
authors: DE
authors: Cole
authors: Fabio
authors: F
authors: Pellegrini
authors: Lucie
authors: L
authors: Canaff
authors: Geoffrey N
authors: GN
authors: Hendy
authors: Leonardo
authors: L
authors: D'Agruma
authors: Leopoldo
authors: L
authors: Zelante
authors: Massimo
authors: M
authors: Carella
authors: Alfredo
authors: A
authors: Scillitani
authors: Vito
authors: V
authors: Guarnieri
mesh_terms: D000293:Adolescent; D002648:Child; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D005260:Female; D018214:Fibroma, Ossifying / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D018095:Germ-Line Mutation; D057809:HEK293 Cells; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D007573:Jaw Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D019913:Nuclear Localization Signals / Q000235:genetics* / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C454900:CDC73 protein, human; D009363:Neoplasm Proteins; D019913:Nuclear Localization Signals; D025521:Tumor Suppressor Proteins