Polymorphisms in the genes encoding members of the tristetraprolin family of human tandem CCCH zinc finger proteins.
The three known mammalian CCCH tandem zinc finger proteins of the tristetraprolin (TTP) class have recently been demonstrated to be mRNA-binding proteins. The prototype, TTP, functions in normal physiology to promote the instability of the tumor necrosis factor alpha (TNFalpha) and granulocyte-macrophage colony-stimulating factor mRNAs. Conversely, these mRNAs are stabilized in TTP-deficient mice, leading to an inflammatory phenotype characterized by overproduction of these cytokines. To explore sequence variations in TTP and its two related proteins, we sequenced genomic DNA encoding the TTP protein (ZFP36) and those of its two known mammalian relatives, ZFP36L1 and ZFP36L2, from 72 to 92 anonymous human subjects from various geographical and ethnic backgrounds. We also sequenced ZFP36 in genomic DNA from 92 subjects exhibiting evidence of excessive TNFalpha action. The resequencing strategy identified 13 polymorphisms in the protein-coding regions of these three genes, of which six would result in amino acid changes; other putative polymorphisms were identified by EST searches. One mutation in ZFP36L1 was a dinucleotide substitution that would prevent splicing of the single intron. This mutation was identified in only one allele of the original 144 sequenced from an adult female Aka Pygmy from the Central African Republic; a second individual with the same variant allele was found by genotyping 58 additional Aka DNA samples. Analysis of mRNA from one of these subject's lymphoblasts confirmed that ZFP36L1 mRNA levels were approximately 50% of those in a comparable sample without the mutation. The functional significance of this and the other polymorphisms identified remains to be determined by both biochemical and population linkage studies.
Blackshear
Perry J
PJ
Office of Clinical Research and Laboratory of Signal Transduction, A2-05 National Institute of Environmental Health Sciences, 111 Alexander Drive, Research Triangle Park, NC 27709, USA.
Phillips
Ruth S
RS
Vazquez-Matias
Johana
J
Mohrenweiser
Harvey
H
D000595:Amino Acid Sequence; D001483:Base Sequence; D051817:Butyrate Response Factor 1; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D006801:Humans; D017874:Immediate-Early Proteins / Q000737:chemistry / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D017354:Point Mutation; D011110:Polymorphism, Genetic / Q000235:genetics*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics; D051816:Tristetraprolin; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D016335:Zinc Fingers
D051817:Butyrate Response Factor 1; D004268:DNA-Binding Proteins; D017874:Immediate-Early Proteins; D014157:Transcription Factors; D051816:Tristetraprolin; D014409:Tumor Necrosis Factor-alpha; C497552:ZFP36 protein, human; C102034:ZFP36L1 protein, human; C091750:ZFP36L2 protein, human