Sidansvarig: Webbredaktion
Sidan uppdaterades: 2012-09-11 15:12
Författare |
Emily Malmberg Thaher Pelaseyed Åsa Petersson Ursula E. Seidler Hugo de Jonge John R. Riordan Gunnar C. Hansson |
---|---|
Publicerad i | Biochemical Journal |
Volym | 410 |
Sidor | 283-289 |
ISSN | 1470-8728 |
Publiceringsår | 2008 |
Publicerad vid |
Institutionen för biomedicin, avdelningen för medicinsk kemi och cellbiologi |
Sidor | 283-289 |
Språk | en |
Länkar |
dx.doi.org/10.1042/BJ20071068 |
Ämnesord | cystic fibrosis transmembrane conductance regulator (CFTR), Muc3, MS, Na+/H+-exchanger regulatory factor 1, (NHERF1), PDZ domain protein, transmembrane mucin |
Ämneskategorier | Medicin och Hälsovetenskap |
The membrane bound mucins have a heavily O-glycosylated extracellular domain, a single pass membrane domain and a short cytoplasmic tail. Three of the membrane bound mucins, MUC3, MUC12 and MUC17, are clustered on chromosome 7 and found in the gastrointestinal tract. These mucins have C-terminal sequences typical for PDZ domain binding proteins. To identify PDZ proteins able to interact with the mucins, we screened PDZ domain arrays using YFP-tagged proteins. MUC17 exhibited a strong binding to PDZK1 whereas the binding to NHERF1 was weak. Furthermore, we showed weak binding of MUC12 to PDZK1, NHERF1 and NHERF2. GST pull-down experiments confirmed that the C-terminal tail of MUC17 co-precipitates with the scaffold protein PDZK1 as identified by mass spectrometry. This was mediated through the C-terminal PDZ-interaction site in MUC17 which was capable of binding to three of the four PDZ domains in PDZK1. Immunostaining of wild-type or Pdzk1-/- mouse jejunum with an antiserum against Muc3(17), the mouse orthologue of human MUC17, revealed strong brush border membrane staining in the wild-type mice compared to an intracellular Muc3(17) staining in the Pdzk1-/- mice. This suggests that Pdzk1 plays a specific role in stabilizing Muc3(17) in the apical membrane of small intestinal enterocytes.