High impact information on Pvr

• The VEGF receptor homolog is expressed in hemocytes, and three VEGF homologs are expressed along hemocyte migration routes [1].
• The oocyte is the source of a ligand for PVR, PDGF/VEGF factor 1 (PVF1) [2].
• Guidance of cell migration by the Drosophila PDGF/VEGF receptor [2].
• The results of genetic and biochemical experiments indicate that PVR activates the JNK pathway [3].
• It was earlier shown that Mbc, a CDM family protein, and its effector, Rac, transduced the guidance signal from PVR during border cell migration [3].

Biological context of Pvr

• Flies hemizygous for the apoptotic genes hid, reaper and grim, or mutant for puckered which encodes a phosphatase that down-regulates the n-Jun-N terminal kinase pathway, lead to the same phenotypes as mutations in PVF1/PVR [4].
• PVF1/PVR signaling and apoptosis promotes the rotation and dorsal closure of the Drosophila male terminalia [4].
• PVR, the Drosophila homolog of the PDGF/VEGF receptor, has been implicated in border cell migration during oogenesis and hemocyte migration during embryogenesis [3].
• In contrast, using both laser ablation and a novel wounding assay that allows localized treatment with inhibitory drugs, we show that PI3K is essential for hemocyte chemotaxis toward wounds and that Pvf signals and PDGF/VEGF receptor expression are not required for this rapid chemotactic response [5].
• These results identify the PDGF/VEGF receptor homolog and one of its ligands as important players in Drosophila hematopoiesis [6].

Anatomical context of Pvr

• We examined the roles of the Drosophila PDGF/VEGF receptor (PVR) in polarized epithelial cells, with specific emphasis on the wing disc epithelium [7].
• Elevation of the level of full-length PVR also gave rise to prominent phenotypes, characterized by higher levels of actin microfilaments at the basolateral areas of the cells and irregular folding of the tissue [7].
• Together, these results suggest that polarized PVR activation is necessary for the proper organization of the wing disc epithelium, by regulating the apical assembly of the actin cytoskeleton [7].
• The Drosophila VEGF receptor homolog is expressed in hemocytes [8].
• In Pvr mutants, a large fraction of the embryonic hemocyte population undergoes apoptosis, and the remaining blood cells cannibalistically phagocytose their dying peers [9].

Associations of Pvr with chemical compounds

• It was previously shown that two receptor tyrosine kinases, epidermal growth factor receptor (EGFR) and PDGF- and VEGF-related receptor (PVR), together contribute to border cell migration [10].

Regulatory relationships of Pvr

• We find that accumulation of Cortactin protein is positively regulated by PVR [11].

Other interactions of Pvr

• Therefore, a complex combination of EGFR and PVR ligands together guide border cells to the oocyte [10].
• We present evidence that Cortactin is one of the factors acting downstream of PVR and Src to stimulate F-actin accumulation [11].
• We find that preventing hemocyte migration by removing the function of the Drosophila VEGF receptor homologue, Pvr, or by disrupting Rac1 function in these cells, inhibits condensation [12].
• PVR plays a critical role via JNK activation in thorax closure during Drosophila metamorphosis [3].
• In the case of Pvr and Alk, this phenotype also is accompanied by lamellocyte formation [13].

Analytical, diagnostic and therapeutic context of Pvr

• In cell culture, we demonstrate that PVR directly controls survival of a hemocyte cell line [9].

References