title: Analysis of alternatively spliced isoforms of human LDL receptor mRNA.
abstract: BACKGROUND
  The low density lipoprotein receptor (LDLR) family is a family of structurally related cell surface receptors with conserved exon/intron organization. Several members of this family have been shown to undergo alternative splicing. However, no alternative splicing of the LDLR pre-mRNA has so far been described.
  
  
  METHODS
  In the present study alternative splicing of human LDLR pre-mRNA has been studied in eight different tissues and four different cell lines using reverse transcription (RT) PCR. A quantitative real-time PCR with exon-exon boundary spanning primers was established to measure the relative amount of two novel isoforms.
  
  
  RESULTS
  Several novel isoforms were identified by RT-PCR of which the isoforms lacking exon 4 or 12 were two of the most prominent. Although highly detectable by RT-PCR, the quantification by real-time PCR revealed low levels of these isoforms.
  
  
  CONCLUSIONS
  Novel isoforms of LDLR mRNA are described. Quantification by real-time PCR of two of the alternatively spliced isoforms revealed low amount of these isoforms in the examined tissues and cell lines. Further investigations are needed to evaluate if these isoforms represent functional transcripts of LDLR mRNA.
authors.affiliation: Medical Genetics Laboratory, Department of Medical Genetics, Rikshospitalet-Radiumhospitalet Medical Center, N-0027 Oslo, Norway.
authors.forename: Kristian
authors.initials: K
authors.lastname: Tveten
authors.forename: Trine
authors.initials: T
authors.lastname: Ranheim
authors.forename: Knut Erik
authors.initials: KE
authors.lastname: Berge
authors.forename: Trond P
authors.initials: TP
authors.lastname: Leren
authors.forename: Mari Ann
authors.initials: MA
authors.lastname: Kulseth
mesh_terms: D017398:Alternative Splicing; D002460:Cell Line; D002478:Cells, Cultured; D006801:Humans; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics* / Q000302:isolation & purification; D011973:Receptors, LDL / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D011973:Receptors, LDL