title: Protein kinase A effects of an expressed PRKAR1A mutation associated with aggressive tumors.
abstract: Most PRKAR1A tumorigenic mutations lead to nonsense mRNA that is decayed; tumor formation has been associated with an increase in type II protein kinase A (PKA) subunits. The IVS6+1G>T PRKAR1A mutation leads to a protein lacking exon 6 sequences [R1 alpha Delta 184-236 (R1 alpha Delta 6)]. We compared in vitro R1 alpha Delta 6 with wild-type (wt) R1 alpha. We assessed PKA activity and subunit expression, phosphorylation of target molecules, and properties of wt-R1 alpha and mutant (mt) R1 alpha; we observed by confocal microscopy R1 alpha tagged with green fluorescent protein and its interactions with Cerulean-tagged catalytic subunit (C alpha). Introduction of the R1 alpha Delta 6 led to aberrant cellular morphology and higher PKA activity but no increase in type II PKA subunits. There was diffuse, cytoplasmic localization of R1 alpha protein in wt-R1 alpha- and R1 alpha Delta 6-transfected cells but the former also exhibited discrete aggregates of R1 alpha that bound C alpha; these were absent in R1 alpha Delta 6-transfected cells and did not bind C alpha at baseline or in response to cyclic AMP. Other changes induced by R1 alpha Delta 6 included decreased nuclear C alpha. We conclude that R1 alpha Delta 6 leads to increased PKA activity through the mt-R1 alpha decreased binding to C alpha and does not involve changes in other PKA subunits, suggesting that a switch to type II PKA activity is not necessary for increased kinase activity or tumorigenesis.
authors.affiliation: Section on Endocrinology and Genetics, Program in Developmental Endocrinology and Genetics, National Institute of Child Health and Human Development, NIH, Bethesda, Maryland 20892, USA.
authors.forename: Elise
authors.initials: E
authors.lastname: Meoli
authors.forename: Ioannis
authors.initials: I
authors.lastname: Bossis
authors.forename: Laure
authors.initials: L
authors.lastname: Cazabat
authors.forename: Manos
authors.initials: M
authors.lastname: Mavrakis
authors.forename: Anelia
authors.initials: A
authors.lastname: Horvath
authors.forename: Sotiris
authors.initials: S
authors.lastname: Stergiopoulos
authors.forename: Miriam L
authors.initials: ML
authors.lastname: Shiferaw
authors.forename: Glawdys
authors.initials: G
authors.lastname: Fumey
authors.forename: Karine
authors.initials: K
authors.lastname: Perlemoine
authors.forename: Michael
authors.initials: M
authors.lastname: Muchow
authors.forename: Audrey
authors.initials: A
authors.lastname: Robinson-White
authors.forename: Frank
authors.initials: F
authors.lastname: Weinberg
authors.forename: Maria
authors.initials: M
authors.lastname: Nesterova
authors.forename: Yianna
authors.initials: Y
authors.lastname: Patronas
authors.forename: Lionel
authors.initials: L
authors.lastname: Groussin
authors.forename: Jérôme
authors.initials: J
authors.lastname: Bertherat
authors.forename: Constantine A
authors.initials: CA
authors.lastname: Stratakis
mesh_terms: D000818:Animals; D019556:COS Cells; D048430:Cell Shape / Q000235:genetics; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit / Q000235:genetics* / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017353:Gene Deletion; D006367:HeLa Cells; D006801:Humans; D009154:Mutation; D009361:Neoplasm Invasiveness / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics*; D011485:Protein Binding; D021122:Protein Subunits / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection
chemical_list: D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit; C517834:PRKAR1A protein, human; D021122:Protein Subunits; D012333:RNA, Messenger; D017868:Cyclic AMP-Dependent Protein Kinases