Expression of novel podocyte-associated proteins sult1b1 and ankrd25

Nephron Exp Nephrol. 2011;117(2):e39-46. doi: 10.1159/000320049. Epub 2010 Aug 18.

Abstract

Background/aims: Podocytes have a unique function in the renal ultrafiltration that is achieved by expressing proteins that are highly specific to podocytes. In this study, we identified two novel podocyte-associated proteins.

Methods: The expression of sult1b1 and ankrd25 in mouse tissues was studied by RT-PCR. The protein expression was studied by generating polyclonal antibodies that were used in Western blotting and immunohistochemistry.

Results: By RT-PCR we detected sult1b1 expression only in glomerular, liver and brain tissues. By immunohistochemistry, sult1b1 was detected in the kidney exclusively in the Golgi apparatus of the podocyte. No expression outside the glomerulus was observed in the kidney. The ankrd25 transcript was detected in most mouse tissues analyzed by RT-PCR. In the kidney, however, immunohistochemistry showed that this protein was expressed only by podocyte, mesangial, and smooth muscle cells. In podocytes, ankrd25 was localized to foot processes.

Conclusions: Identification of these two novel glomerulus-associated proteins opens up possibilities to investigate their role in the renal filter physiology and diseases. We speculate that sult1b1 may be involved in the sulfonylation of podocyte protein podocalyxin, whereas ankrd25 may contribute to controlling actin dynamics in podocyte foot processes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Ankyrin Repeat
  • Base Sequence
  • Blotting, Western
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism*
  • DNA Primers / genetics
  • Gene Expression
  • Humans
  • Immunohistochemistry
  • Kidney / cytology
  • Kidney / metabolism
  • Mice
  • Podocytes / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sulfotransferases / genetics*
  • Sulfotransferases / metabolism*
  • Tissue Distribution
  • Tumor Suppressor Proteins / metabolism

Substances

  • Carrier Proteins
  • DNA Primers
  • KANK1 protein, human
  • Kank1 protein, mouse
  • Tumor Suppressor Proteins
  • Sulfotransferases
  • iodothyronine sulfotransferase