PESCADILLO - Wnt-like signaling?
From Purdue Genomics Database Facility
Victor A. Albert
Whereas STERILE APETALA (SAP) is a single-copy gene with mixed conservation among land plants, other single copy genes appear ubiquitous among both animals and plants. This contrast is an important one if single-copy genes are often maintained as such because of hub-like, dosage dependent effects.
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Pescadillo was originally isolated as a single-copy gene from zebrafish, and was subsequently shown to have single homologs in other eukaryotes including human. Zebrafish pescadillo is characterized by pleiotropic embryonic defects such reduced eye, brain and skeletal development, shortened fins, non-expanded liver and gut, and death after only a few days. Xenopus pescadillo has perhaps been best studied, and there it has been suggested to be a potential direct (or near direct) target of non-canonical Wnt-4 signalling.
- This suggestion is extremely exciting given the similiarities drawn between brassinosteroid signaling in Arabidopsis and the Wnt pathway in animals.
Xenopus pescadillo has been shown to regulate both cell proliferation and apoptosis, as well as cell migration in the cranial neural crest. In other words, pescadillo is a highly multifunctional protein, and its single-copy status suggests that it operates as a hub for incoming and outgoing signals and interactions. Human pescadillo has been associated with tumorigenesis (it contains a BRCT domain, as is found in BRCA1).
As with other eukaryotes, pescadillo-like proteins are found in green plants. I have found what appear to be single pescadillo-like proteins in Arabidopsis, Medicago, rice, Selaginella (2 alleles), Physcomitrella, Ostreococcus, and Chlamydomonas. See the preliminary tree and alignment below (the Arabidopsis homolog is highlighted in the alignment).
As such, the potential hub-like function of pescadillo-like proteins appears conserved from animals to plants. Perhaps it is also the case that plant pescadillo-like proteins have highly pleiotropic effects in both cell proliferation and apoptosis. No phenotypes are available at TAIR (At5g14520), which is perhaps not surprising.
Note the gene descriptors in the tree and alignment.
