Jadranka Loncarek, Ph.D.

The long-term goal of our laboratory is to understand the fundamentals of centrosome biology.

Centrosomes are minute multifunctional membrane-less organelles present in only two copies in a typical cycling animal cell. In the core of a centrosome is a nine-fold symmetrical cylindrical microtubule-based structure called a centriole, which organizes the second major part of the centrosome called pericentriolar material which is a large and dynamic multiprotein complex and the site of many centrosomal functions. A typical somatic cell has only two centrosomes, often localized in the physical center of the cell near the nucleus. Centrosomes perform vital cellular functions such as microtubule nucleation, organization of the bipolar mitotic spindle poles during cell division, cellular signaling, and they influence tissue architecture and cell motility. Centrosomes also organize sensory and motile cilia, which are critically important for development and tissue homeostasis.

Centrosomes in disease: Supernumerary and/or structurally aberrant centrioles and centrosomes perturb mitosis, tissue architecture, cell signaling, and can promote tumorigenesis and tumor invasiveness. Centriolar and ciliary defects are, in addition, an underlying cause of genetic disorders known as ciliopathies. Therefore, understanding the molecular mechanisms that regulate centrosome number, structure, and function is a paramount for understanding centrosome and cilia- related diseases.

Our research: Unlike most cellular organelles, which are present in variable shapes and numbers, centrosome architecture and number are stringently controlled. However, how cells control centrosome assembly has yet to be elucidated mechanistically. We seek to develop an in-depth understanding of the mechanisms that regulate centriole and centrosome number and ensure centriole and centrosome numerical and structural stability (and how is this stability lost in pathologies like cancer). We aim to understand the roles of various cell cycle- and mitotic- regulators in centrosome biogenesis and how they coordinate centrosome assembly and with other cell cycle events. Finally, we seek to unravel centrosomal architecture in nano scale resolution, to understand how intra-centrosomal dynamics of centrosomal proteins relates to centrosome functions.

Methodology: We use a multipronged experimental approach combining molecular biology, biochemistry, and genetics, with a variety of cutting-edge microscopy approaches ranging from live-cell and super resolution microscopy, expansion microscopy, to transmission electron microscopy and correlative light and electron microscopy.

If you are interested in our work and wish to inquire about open postdoctoral or postbac positions, please send a C.V., a statement of research interests, and the names and contact details of 3 references to jadranka.loncarek@nih.gov.

Dr. Jadranka Loncarek joined the Laboratory of Protein Dynamics and Signaling as an NIH Earl Stadtman Tenure Track Investigator. She obtained her Ph.D. from the Faculty of Sciences at Zagreb University, Croatia, in cell and molecular biology. She completed her postdoctoral training in the laboratory of Dr. Alexey Khodjakov at Wadsworth Center, Albany, New York, where she studied the mechanisms of centriole duplication and mitotic spindle formation. Her current research focuses on elucidating the molecular mechanism of centrosome biogenesis and their function, with particular attention on numerical control of centrosome formation in non-transformed and cancerous human cells. She received tenure from NIH in 2020.