title: Expression analysis of the human adducin gene family and evidence of ADD2 beta4 multiple splicing variants.
abstract: Adducin is a cytoskeleton heterodimeric protein. Its subunits are encoded by three related genes (ADD1, ADD2, and ADD3) which show alternative spliced variants. Adducin polymorphisms are involved in blood pressure regulation in humans and rats. We have analyzed mRNA distribution of ADD gene family in human tissues and cells with Real-Time TaqMan RT-PCR. Whereas ADD1 is ubiquitously distributed, ADD3 is more expressed in kidney medulla and cortex than in fetal kidney, while in adult liver it is less abundant than in fetal liver. ADD2 beta1 and beta4 variants show the same pattern of distribution with the highest expression in brain, fetal liver, and kidney. Conventional RT-PCR identified new beta4 variants. Beta4a is characterized by an in-frame insertion of 21 nucleotides upstream exon 15 predicting a 7 amino acids longer protein with a similar C-terminus region. It is coexpressed with beta1 and beta4 in several tissues. Fetal kidney shows further beta4b, beta4c and beta4d variants containing internal exon deletions that enormously modify the predicted NH(2) and central regions. Our findings could help one to understand the functional role of adducin variants in specific tissues and cells.
authors.affiliation: Division of Nephrology, Dialysis and Hypertension, Università Vita-Salute, San Raffaele Hospital, Milan, Italy. lorena.citterio@hsr.it
authors.forename: Lorena
authors.initials: L
authors.lastname: Citterio
authors.forename: Laura
authors.initials: L
authors.lastname: Tizzoni
authors.forename: Marco
authors.initials: M
authors.lastname: Catalano
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Zerbini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bianchi
authors.forename: Cristina
authors.initials: C
authors.lastname: Barlassina
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002148:Calmodulin-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D008969:Molecular Sequence Data; D009928:Organ Specificity; D019154:Protein Splicing / Q000235:genetics; D021122:Protein Subunits; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D016415:Sequence Alignment / Q000379:methods; D014018:Tissue Distribution; D000099291:Adducins
chemical_list: D002148:Calmodulin-Binding Proteins; D021122:Protein Subunits; D012333:RNA, Messenger; D000099291:Adducins; C102021:ADD3 protein, human