Identification and functional analysis of CITED2 mutations in patients with congenital heart defects.
Recent reports have demonstrated that mice lacking the transcription factor Cited2 die in utero showing various cardiac malformations. We present for the first time functionally relevant mutations of CITED2 in patients with congenital heart defects (CHDs). CITED2 encodes a CREBBP/EP300 interacting transcriptional modulator of HIF1A and TFAP2. To study the potential impact of sequence variations in CITED2 for CHDs in humans, we screened a cohort of 392 well-characterized patients and 192 control individuals using DHPLC, sequencing, and Amplifluor genotyping techniques. We identified 15 CITED2 nucleotide alterations. Seven of these alterations were found only in CHD patients and were not detected in controls, including three mutations leading to alterations of the amino acid sequence (p.Ser170_Gly178del, p.Gly178_Ser179ins9, and p.Ser198_Gly199del). All three of these amino acid changing mutations cluster in the serine-glycine-rich junction of the protein, to which no functionality had heretofore been assigned. Here we show that these mutations significantly reduce the capacity of CITED2 to transrepress HIF1A, and that the p.Ser170_Gly178del mutation significantly diminishes TFAP2C coactivation. This reveals a modifying role for the serine-glycine-rich region in CITED2 function. In summary, the observation of these mutations in patients with septal defects indicates that CITED2 has a causative impact in the development of CHD in humans.
Sperling
Silke
S
Max Planck Institute for Molecular Genetics, Berlin, Germany. sperling@molgen.mpg.de
Grimm
Christina H
CH
Dunkel
Ilona
I
Mebus
Siegrun
S
Sperling
Hans-Peter
HP
Ebner
Arno
A
Galli
Raffaello
R
Lehrach
Hans
H
Fusch
Christoph
C
Berger
Felix
F
Hammer
Stefanie
S
D000595:Amino Acid Sequence; D002460:Cell Line; D015331:Cohort Studies; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005786:Gene Expression Regulation; D005787:Gene Frequency; D005820:Genetic Testing; D006239:Haplotypes; D006330:Heart Defects, Congenital / Q000235:genetics*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D011993:Recombinant Fusion Proteins / Q000032:analysis; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D050656:Transcription Factor AP-2 / Q000235:genetics / Q000378:metabolism
C486381:CITED2 protein, human; D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C493679:TFAP2C protein, human; D015534:Trans-Activators; D050656:Transcription Factor AP-2