Quality control systems facilitate polypeptide folding and degradation to maintain protein homeostasis. Molecular chaperones promote folding, whereas the ubiquitin/proteasome system mediates degradation. We show here that Saccharomyces cerevisiae Ubr1 and Ubr2 ubiquitin ligases promote degradation of unfolded or misfolded cytosolic polypeptides.
View Article and Find Full Text PDFChronic myelogenous leukemia is a malignant disease of the hematopoietic stem cell compartment, which is characterized by expression of the BCR-ABL fusion protein. Expression of BCR-ABL allows myeloid cells to grow in the absence of the growth factors interleukin-3 and granulocyte-macrophage colony-stimulating factor. The tyrosine kinase activity of BCR-ABL constitutively activates signaling pathways associated with Ras and its downstream effectors and with the Jak/STAT pathway.
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