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Dictyostelium RbrA is a putative Ariadne‐like ubiquitin ligase required for development
Author(s) -
Pearson Lacey,
Johnson Trudi,
Lindsey David
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a547-a
Subject(s) - ubiquitin ligase , dictyostelium , ubiquitin , microbiology and biotechnology , computational biology , biology , chemistry , genetics , gene
The RBR family of ubiquitin ligases is a large and complex family with members present in animals, plants, fungi, and protists. The Ariadne subfamily appears to be the most ancient. The Dictyostelium rbrA gene encodes a protein with similarity to Ariadne ubiquitin ligases. Disruption of rbrA results in cells that form defective slugs that cannot produce fruiting bodies. Prestalk cell numbers were greatly reduced in rbrA‐ slugs, and these cells did not localize to the tip of the slug. Developing rbrA‐ cells on conditioned medium does not rescue the defect. However, mixing a few wild‐type cells with developing rbrA‐ cells did partially rescue the defect. The chimeric slugs formed fruiting bodies; however, rbrA‐ cells in the sori produce a low percentage of viable spores. When chimeras containing 90% rbrA cells were stained with fluorescein diacetate and propidium iodide, some sori stained like wild‐type while others were red indicating cell death. To identify other genes involved in the rbrA pathway, we screened for second site suppressors of the rbrA mutation. In one putative suppressor, SRA1, normal cell‐type distribution appears to be restored. The disrupted gene in SRA1 encodes a hypothetical 163 kDa protein.