Details

Autor(en) / Beteiligte

• Vázquez-Carretero, María D.
• García-Miranda, Pablo
• Balda, María S.
• Matter, Karl
• Peral, María J.
• Ilundain, Anunciación A.

Titel

Small and large intestine express a truncated Dab1 isoform that assembles in cell-cell junctions and co-localizes with proteins involved in endocytosis

Ist Teil von

• Biochimica et biophysica acta. Biomembranes, 2018-05, Vol.1860 (5), p.1231-1241

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2018

Quelle

MEDLINE

Beschreibungen/Notizen

• Disabled-1 (Dab1) is an essential intracellular adaptor protein in the reelin pathway. Our previous studies in mice intestine showed that Dab1 transmits the reelin signal to cytosolic signalling pathways. Here, we determine the Dab1 isoform expressed in rodent small and large intestine, its subcellular location and co-localization with clathrin, caveolin-1 and N-Wasp. PCR and sequencing analysis reveal that rodent small and large intestine express a Dab1 isoform that misses three (Y198, Y200 and Y220) of the five tyrosine phosphorylation sites present in brain Dab1 isoform (canonical) and contains nuclear localization and export signals. Western blot assays show that both, crypts, which shelter progenitor cells, and enterocytes express the same Dab1 isoform, suggesting that epithelial cell differentiation does not regulate intestinal generation of alternatively spliced Dab1 variants. They also reveal that the canonical and the intestinal Dab1 isoforms differ in their total degree of phosphorylation. Immunostaining assays show that in enterocytes Dab1 localizes at the apical and lateral membranes, apical vesicles, close to adherens junctions and desmosomes, as well as in the nucleus; co-localizes with clathrin and with N-Wasp but not with caveolin-1, and in Caco-2 cells Dab1 localizes at cell-to-cell junctions by a Ca2+-dependent process. In conclusion, the results indicate that in rodent intestine a truncated Dab1 variant transmits the reelin signal and may play a role in clathrin-mediated apical endocytosis and in the control of cell-to-cell junction assembly. A function of intestinal Dab1 variant as a nucleocytoplasmic shuttling protein is also inferred from its sequence and nuclear location. [Display omitted] •Rodent intestine expresses a truncated Dab1 not regulated by cell differentiation.•Dab1 localizes at the enterocytes cell membrane, cytosol and nucleus.•Dab1 localizes at cell-cell junctions, in Caco2 this localization is Ca2+-dependent.•Intestinal Dab1 co-localizes with clathrin and with N-Wasp at apical vesicles.•Intestinal Dab1 may function in endocytosis, cell-cell adhesion and nucleus processes.