Optical tweezers help researchers uncover key mechanics in cellular communication

June 4, 2012

(Credit: Bhupinder Shergill et al./Developmental Cell)

By using a laser microbeam technology called optical tweezers, UC Irvine and UCLA researchers have uncovered fundamental properties of a key molecular signaling system involved with development, cancer, and cardiovascular disease.

UCI’s Elliot Botvinick and UCLA’s Gerry Weinmaster used optical tweezers to detect and measure the mechanical force produced by cells when bound to Notch, a cellular pathway that ensures the correct cell types form at a precise time and location in the body.

“The Notch network is used repeatedly during the development of almost every cell type and must be tightly controlled, as inappropriate communication causes developmental defects and cancer,” said Weinmaster, a professor of biological chemistry and researcher at UCLA’s Jonsson Comprehensive Cancer Center.

“Successful design and generation of Notch therapeutics demands a solid understanding of the basic mechanics of the Notch network.”

“Optical tweezers act as tiny tractor beams that can hold and manipulate microscopic beads coated with specific molecules,” said Botvinick, an assistant professor of biomedical engineering and surgery affiliated with the Beckman Laser Institute and The Edwards Lifesciences Center for Advanced Cardiovascular Technology at UCI.

“When cells bind to and pull on the beads, researchers can measure cell-generated forces that are billions of times smaller than the weight of one teaspoon of sugar.”

Using this technology, the UCI-UCLA team found that communication via the Notch network involves a sort of tug-of-war between neighboring cells in which Notch molecules are unraveled by force to reveal hidden elements important for cell-to-cell communication.

Together with biochemical and biological cell analyses, their findings provide compelling evidence that pulling on Notch opens a network to deliver instructions for specific cellular responses.

The research sheds new light on the role of cells’ neighbors in the development and regulation of tissue and advances efforts to create new therapeutics.

Ref.: Bhupinder Shergill et al., Optical Tweezers Studies on Notch: Single-Molecule Interaction Strength Is Independent of Ligand Endocytosis, Developmental Cell, 2012, DOI: 10.1016/j.devcel.2012.04.007