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Yiannis Ioannou

  • PROFESSOR Genetics and Genomic Sciences
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  • B.A., Baruch College, CUNY

  • Ph.D., Mount Sinai School of Medicine


    Yiannis A. Ioannou, Ph.D.; Mount Sinai School of Medicine

    Associate Professor, Department of Genetics and Genomic Sciences and the Department of Gene and Cell Medicine, Box 1498
    Training Area(s): GGS*, MDT, MCBD
    Lab Location: East Building Rm 14-52 Lab, 14-70A Office
    Phone: (212) 659-6720  
    Web Page:



Specific Clinical/Research Interest: Molecular genetics

Summary of Research Studies:
Our lab is involved in a number of projects that center on the biology, function and diseases of the endosomal/lysosomal (E/L) system. In addition, we are developing methods to treat lysosomal diseases via enzyme and gene therapy approaches. See our website for details. Some brief examples of our work are given below: Subcellular Cholesterol/lipid Transport. Although the intercellular transport of cholesterol from the liver to peripheral tissues has been intensively studied, little is known about its egress from the E/L system, its intracellular transport and the proteins involved in this process. The existence of such proteins is highlighted by the autosomal recessive disorders, Niemann-Pick C (NPC) disease, in which cholesterol accumulates in lysosomes and leads to progressive neurodegeneration and Tangier disease in which cholesterol efflux at the plasma membrane is defective. Our overall objective is to identify and characterize the various components of the intracellular cholesterol and lipid transport machinery and determine their function and interactions. Proteomics of the E/L system. Cell Proliferation and Apoptosis: It is becoming clear that the lysosome has a greater role in cellular processes than was originally proposed. Our studies focus on the isolation and purification of intact endosomes and lysosomes. These organelles are then characterized for their membrane composition to identify novel, membrane proteins. We have established a novel method for the isolation and characterization of endosomes and lysosomes. A long-term goal is to identify all the components of the endosomal/lysosomal apparatus using 2D electrophoresis and tandem mass spectroscopy. Therapy for Diseases that Affect the CNS. Effective gene therapy strategies for the treatment of human disease still remain highly experimental due to difficulties encountered in the actual application of many gene therapy schemes. Thus, we are developing novel approaches to address these limitations. Our strategies focus on "Bypass Therapy" an approach aiming at stimulating alternate pathways to bypass a cellular block caused by a specific gene defect.


Davies JP, Ioannou YA. The role of NPC1L1 in the transport of lipid ligands and their homeostasis. Curr Opin Lipidology 2006; 17: 221-226.

Ioannou YA. Guilty until proven innocent: The case of Niemann-Pick C and cholesterol. Trends Biochem Sci 2005; 30(9): 498-505.

Davies JP, Scott C, Ioannou YA, Liapis A, Oishi K. Inactivation of the NPC1L1 causes multiple lipid transport defects and protects against diet-induced hypercholesterolemia. J Biol Chem 2005; 280(13): 12710-12720.

Scott C, Ioannou YA, Davies JP, Higgins ME. Targeting of NPC1 to late endosomes involves multiple signals, including one residing within the putative sterol-sensing domain. J Biol Chem 2004; 279(46): 48214-48223.

Scott C, Ioannou YA. The NPC1 Protein: Structure Implies Function. Bioch Biophys Acta 2004; 1685(1-3): 8-13.

Ioannou YA, Enriquez A, Benjamin C. Gene Therapy for Lysosomal Storage Diseases. Expert Opin Biol Ther 2003; 3: 789-801.

Ioannou YA. Defects in transmembrane proteins. In: Platt FM, Walkley SU, editors. Lysosomal Disorders of Brain. Oxford University Press (in press);.

Walter M, Davies JP, Ioannou YA. Telomerase immortalization upregulates Rab9 expression and restores LDLcholesterol egress from Niemann-Pick C1 late endosomes. J Lipid Res 2003; 44(2): 243-253.

Industry Relationships

Physicians and scientists on the faculty of the Icahn School of Medicine at Mount Sinai often interact with pharmaceutical, device and biotechnology companies to improve patient care, develop new therapies and achieve scientific breakthroughs. In order to promote an ethical and transparent environment for conducting research, providing clinical care and teaching, Mount Sinai requires that salaried faculty inform the School of their relationships with such companies.

Below are financial relationships with industry reported by Dr. Ioannou during 2015 and/or 2016. Please note that this information may differ from information posted on corporate sites due to timing or classification differences.


  • Neurotrope BioScience

Royalty Payments:

  • Genzyme Corporation; Life Technologies Corporation

Equity (Stock or stock options valued at greater than 5% ownership of a publicly traded company or equity of any value in a privately held company)

  • Dual Therapeutics

Mount Sinai's faculty policies relating to faculty collaboration with industry are posted on our website. Patients may wish to ask their physician about the activities they perform for companies.

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Icahn (East) Building Floor 14 Room 14-70A
1425 Madison Avenue
New York, NY 10029

Tel: 212-659-6720
Fax: 212-659-5657


Icahn (East) Building Floor 14 Room 70C
1425 Madison Avenue
New York, NY 10029


Icahn (East) Building Floor 14 Room 52
1425 Madison Avenue
New York, NY 10029