Work

Loss-of-Function in theDeltaRFAllele Is Due to a Failure of the Delta Protein to Reach the Cell Surface

Year: 2007

Type: article

Abstract: Endocytosis of the Delta ligand presumably drives "trans-endocytosis" of Notch resulting in proteolytic activation of the receptor. This model is founded in Delta mutants that reportedly fail to undergo endocytosis. One such allele, DlRF, gives a temperature-sensitive loss-of-function, purported to be an endocytosis mutant. Here we show that in lineages of Delta-expressing larval neurons the DlRF protein fails to localize to neurites consistent with a failure in trafficking to the plasma membrane. We find that the DlRF allele carries two mutations, G305E and C348Y, in the extracellular epidermal growth factor-like (EGF) repeats 3 and 4. Co-expression of GFP-tagged DlRF and RFP-tagged wild-type Delta (DlWT) in S2 cells demonstrates complete segregation of the proteins at 30ºC with DlRF failing to localize to the plasma membrane. As well, DlRF fails to undergo a characteristic proteolytic processing. Altogether the data indicate that the DlRF allele has limited utility for studying Delta endocytosis mechanisms but is well suited as a tool for loss-of-function studies.

Source: Fly

DOI: 10.4161/fly.4531

Authors: Anton Delwig, Matthew D. Rand

Institution: University of Vermont

Language: English

Topic: Developmental Biology and Gene Regulation

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze

Funders: National Institutes of Health, National Center for Research Resources

Awards: G2335192701, G3818437434