Immunohistochemical localisation of pterin-4α-carbinolamine dehydratase in rat peripheral organs

Abstract

The bifunctional protein PCD/DCoH is both a pterin-4alpha-carbinolamine dehydratase (PCD) involved in the recycling of tetrahydrobiopterin (BH4) and a dimerisation cofactor (DCoH) of the hepatic nuclear factor 1alpha (HNF-1alpha). An antiserum raised against rat PCD/DCoH was used to localise the protein in peripheral organs. In liver, all the hepatocytes but not the other cell types are immunoreactive. In kidney, the protein is prevalent in the proximal and distal convoluted tubules. In adrenals, all the cells of the medulla are labelled. Positive nerve cells occur in myenteric ganglia of the whole gastrointestinal tract and in the intestinal submucous ganglia. Many positive endocrine cells are present in the epithelium. The immunoreactivity is either cytoplasmic (hepatocytes, convoluted tubules of the kidney and part of the gastrointestinal endocrine cells) or prominently nuclear (kidney collecting tubules, adrenals, intestinal neural plexuses and part of the gastrointestinal endocrine cells). Our results show that PCD/DCoH is present in cells expressing enzymes that use BH4 as a cofactor and/or HNF-1alpha. In addition, PCD/DCoH is present in other cells, for example, neurons in the submucosal plexus. This fact and the prominent nuclear immunoreactivity found in all the positive cells derived from the neural crests argue in favour of a new, still unknown function for the protein.

Mutations in PCBD1 Cause Hypomagnesemia and Renal Magnesium Wasting

“…Based on the serum Ca 2+ levels and urinary Ca 2+ excretion values, it is likely that, in our patients, the DCT is primarily affected. 26 Because Pcbd1 was present in the cytosol of renal cells, we hypothesized that the relative abundance of PCBD1 and HNF1B in the kidney may favor the cytosolic localization. Nevertheless, a nuclear localization of PCBD1 in the kidney could occur according to tissue-specific dynamics of the PCBD1-HNF1B complex.…”

“…Beat Thöny). 26 The following day, sections were washed and incubated with a goat anti-rabbit secondary antibody coupled to Alexa Fluor 488 (A11008, 1:300; Invitrogen) for 1 hour at room temperature. Kidney sections were costained for Bcrp, Tamm Horsfall, NCC, calbindin-D 28k (D28K), or Aqp2.…”

Genomewide Identification of Genes Under Directional Selection: Gene TranscriptionQST Scan in Diverging Atlantic Salmon Subpopulations

“…Hence, the nucleolar RNA helicase II is a multifunctional protein that is notably implicated in rRNA biosynthesis and in the regulation of c-Jun-mediated gene expression (Yang et al 2005). Pterin-4-a-carbinolamine dehydratase, apart from its role in tetrahydrobiopterin biosynthesis, is also known as a dimerization factor of the hepatocyte nuclear factor (HNF) 1 a, one of the master regulators of hepatocyte and pancreatic islet transcription (Resibois et al 1999).…”

Histochemistry and cell biology: what's in a name?

“…The enzyme pterin-4alpha-carbinolamine dehydratase represents a dimerization cofactor of the hepatic nuclear factor 1alpha and was localized in rat peripheral organs. Inter alias, prominent nuclear immunoreactivity was found in cells derived from the neural crests which argues in favor of a new, still unknown function for the protein (Resibois et al 1999). A novel feature occurring during terminal differentiation of erythroblasts consisting of heterogeneous ectopic RNPderived structures which appear in parallel with chromatin condensation was discovered (Biggiogera et al 1999).…”