Gata3-deficient mice develop parathyroid abnormalities due to dysregulation of the parathyroid-specific transcription factor Gcm2
Irina V. Grigorieva, … , Frank Grosveld, Rajesh V. Thakker
Irina V. Grigorieva, … , Frank Grosveld, Rajesh V. Thakker
Published May 17, 2010
Citation Information: J Clin Invest. 2010;120(6):2144-2155. https://doi.org/10.1172/JCI42021.
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Research Article Endocrinology

Gata3-deficient mice develop parathyroid abnormalities due to dysregulation of the parathyroid-specific transcription factor Gcm2

Abstract

Heterozygous mutations of GATA3, which encodes a dual zinc-finger transcription factor, cause hypoparathyroidism with sensorineural deafness and renal dysplasia. Here, we have investigated the role of GATA3 in parathyroid function by challenging Gata3+/– mice with a diet low in calcium and vitamin D so as to expose any defects in parathyroid function. This led to a higher mortality among Gata3+/– mice compared with Gata3+/+ mice. Compared with their wild-type littermates, Gata3+/– mice had lower plasma concentrations of calcium and parathyroid hormone (PTH) and smaller parathyroid glands with a reduced Ki-67 proliferation rate. At E11.5, Gata3+/– embryos had smaller parathyroid-thymus primordia with fewer cells expressing the parathyroid-specific gene glial cells missing 2 (Gcm2), the homolog of human GCMB. In contrast, E11.5 Gata3–/– embryos had no Gcm2 expression and by E12.5 had gross defects in the third and fourth pharyngeal pouches, including absent parathyroid-thymus primordia. Electrophoretic mobility shift, luciferase reporter, and chromatin immunoprecipitation assays showed that GATA3 binds specifically to a functional double-GATA motif within the GCMB promoter. Thus, GATA3 is critical for the differentiation and survival of parathyroid progenitor cells and, with GCM2/B, forms part of a transcriptional cascade in parathyroid development and function.

Authors

Irina V. Grigorieva, Samantha Mirczuk, Katherine U. Gaynor, M. Andrew Nesbit, Elena F. Grigorieva, Qiaozhi Wei, Asif Ali, Rebecca J. Fairclough, Joanna M. Stacey, Michael J. Stechman, Radu Mihai, Dorota Kurek, William D. Fraser, Tertius Hough, Brian G. Condie, Nancy Manley, Frank Grosveld, Rajesh V. Thakker

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Figure 3

Mapping of the GCMB transcription start sites by 5' RACE.

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Mapping of the GCMB transcription start sites by 5' RACE. (A) Representa...
(A) Representation of human GCMB gene showing coding exons (white boxes) and 2 alternatively transcribed first exons (1 and 1a), which contain 5' UTRs (gray boxes). Transcription start sites are marked +1 and represent the longest 5' RACE amplicons. Primer sequences (arrows; forward, F1 and F1a; and reverse, R1 and R2) used for amplification of exon 1a and exon 1 are shown. (B) Detection of transcript-specific PCR products after 20 cycles of amplification using human parathyroid tumor RNA, at 2 concentrations (n, neat; 1/20, 20-fold dilution of neat). The splice variant has a shorter exon 1 and yields products of 331 bp and 454 bp. (C) Representation of primer positions and expected sizes of transcripts. (D) Human GCMB 5' upstream sequence. Locations of previously reported (32) transcription start site (*) isolated from human fetal brain and one identified (TSS and +1) from human parathyroids by this study are indicated. An additional transcription start site that was also identified in a splice variant (SV) is shown. Putative GATA3-binding sites (A–C) are in bold; GATA motifs in the reverse orientation are indicated as i and ii; oligonucleotide sequences used for EMSAs are solid underlines; forward primers (Luc-c+ and Luc-c–) used for the luciferase reporter constructs are indicated by arrows; GCMB-RX primer is indicated by the broken underline; and putative TATA box is boxed.