Eukaryotic cells contain a variety of discrete membrane-enclosed organelles. This highly compartmentalized organization is essential to the normal functioning of the cell. Each of these subcellular compartments has unique structural and functional characteristics which are conferred by particular proteins, lipids and/or carbohydrates that comprise them. The lysosome is the major organelle responsible for intracellular degradation in mammalian cells. It contains numerous soluble hydrolases as well as a variety of membrane-associated proteins. Tay Sachs disease, pseudo-Hurler polydystrophy and I cell disease are three of over thirty human genetic disorders which are known to result from the absence of certain proteins in the lysosome. Many of these diseases specifically result from the improper sorting of these proteins. This correlation between sorting defects and disease states underscores the importance of correct protein sorting in cell physiology. The investigators long-term goal is to develop a precise understanding of the molecular events involved in the recognition, sorting and transport of proteins to the lysosome-like vacuole in yeast cells. The investigator will use yeast as a model system to study these problems since the pathways used for protein transport appear to be very similar to those in animal cells, and in addition yeast are amenable to useful genetic approaches which are not as applicable to higher eukaryotes. In this proposal, the investigators will focus on analyzing factors involved in delivery of membrane-associated vacuolar proteins. Initial studies of alkaline phosphatase (ALP) indicate that it is a membrane protein that is delivered to the vacuole by a mechanism that is at least in part different from that used by soluble vacuolar hydrolases. Furthermore, the spatial location of the ALP targeting signal suggests that differences in sorting may reflect an interaction with unique sorting components such as a specific receptor. The investigator will further characterize the vacuolar sorting signal in ALP and will attempt to identify the ALP receptor through a combination of biochemical and genetic approaches. In addition, the investigator will utilize a gene fusion approach to select mutants which are defective in the localization of this protein. These mutants should allow the investigator to define components of the sorting and transport apparatus that recognize and target this protein to the vacuole membrane. These new mutants will be compared with previously identified mutants which missort soluble vacuolar hydrolases. An identification of the sorting determinant in ALP coupled with a characterization of the genes involved in its recognition and delivery should further our understanding of the transport process.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Program Officer
Shapiro, Bert I
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Michigan Ann Arbor
Schools of Arts and Sciences
Ann Arbor
United States
Zip Code
Khoriaty, Rami; Hesketh, Geoffrey G; Bernard, Amélie et al. (2018) Functions of the COPII gene paralogs SEC23A and SEC23B are interchangeable in vivo. Proc Natl Acad Sci U S A 115:E7748-E7757
Song, Xinxin; Zhu, Shan; Chen, Pan et al. (2018) AMPK-Mediated BECN1 Phosphorylation Promotes Ferroptosis by Directly Blocking System Xc- Activity. Curr Biol 28:2388-2399.e5
Yao, Zhiyuan; Liu, Xu; Klionsky, Daniel J (2018) MitoPho8?60 Assay as a Tool to Quantitatively Measure Mitophagy Activity. Methods Mol Biol 1759:85-93
Kondratskyi, Artem; Kondratska, Kateryna; Skryma, Roman et al. (2018) Ion channels in the regulation of autophagy. Autophagy 14:3-21
Gatica, Damián; Lahiri, Vikramjit; Klionsky, Daniel J (2018) Cargo recognition and degradation by selective autophagy. Nat Cell Biol 20:233-242
Liu, Xu; Klionsky, Daniel J (2018) Regulation of autophagic lysosome reformation by kinesin 1, clathrin and phosphatidylinositol-4,5-bisphosphate. Autophagy 14:1-2
Delorme-Axford, Elizabeth; Klionsky, Daniel J (2018) Secretory autophagy holds the key to lysozyme secretion during bacterial infection of the intestine. Autophagy 14:365-367
Galluzzi, Lorenzo; Vitale, Ilio; Aaronson, Stuart A et al. (2018) Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018. Cell Death Differ 25:486-541
Li, Changfeng; Zhang, Ying; Cheng, Xing et al. (2018) PINK1 and PARK2 Suppress Pancreatic Tumorigenesis through Control of Mitochondrial Iron-Mediated Immunometabolism. Dev Cell 46:441-455.e8
van Beek, Nienke; Klionsky, Daniel J; Reggiori, Fulvio (2018) Genetic aberrations in macroautophagy genes leading to diseases. Biochim Biophys Acta Mol Cell Res 1865:803-816

Showing the most recent 10 out of 292 publications