Since Robert Hooke first observed cork under a microscope in 1665, cell biologists have been trying to understand the complex structure of these tiny life units. Presenters at a Symposium on the Structure of the Cell, slated for Sunday, December 3, at 8:00 am at the 2017 ASCB|EMBO Meeting, will discuss current knowledge and exciting state-of-the-art techniques used to reveal the mysteries of the cell’s microscopic realm.

Studying purified cell cultures in a test tube or Petri dish can tell only part of the cell’s story. Ideally, cell biologists ought to study cells in the environments where they grow. This is one of the topics that will be covered by Wolfgang Baumeister of the Max Planck Institute of Biochemistry. Baumeister’s talk, “Cryo-Electron Tomography: Opportunities and Challenges of Structural Biology in Situ,” will explain how cryo-electron tomography (cryo-ET) can help elucidate the molecular architecture of unperturbed cellular environments.

Multispectral image of six organelles visualized by 3D lattice light sheet microscopy (Image: Alex Valm, Sarah Cohen, and Jennifer Lippincott-Schwartz)

As the name suggests, cryo-ET takes frozen hydrated cells and dissects their supramolecular architecture in three dimensions at nanometer resolution. The technique is similar to other tomographic techniques in that it processes two-dimensional images acquired of a cell structure from different viewing angles and then reconstructs that object in three dimensions, Baumeister explained in a recent review on the subject. Baumeister predicts that one day near-atomic resolution of cellular structures may be possible.

“Unraveling the Spatial and Temporal Dynamics of Subcellular Organelles” is the title of the talk by Jennifer Lippincott-Schwartz, Janelia Research Campus/HHMI. In the Lippincott-Schwartz lab, the goal is to “understand the interplay of membrane-bound organelles, cytoskeletal structure, and metabolism as it relates to the organization and function of neurons, and the cells they interact with.”

“On a small scale, we are interested in mapping out the spatial organization, stoichiometry, and dynamics of proteins as they interact with each other and with different parts of the cell,” writes Lippincott-Schwartz. “On a larger scale, we are trying to decipher how complex cellular behaviors arise, including cell crawling, polarization, cell–cell contact, cytokinesis, cell fate determination, viral budding, and intercellular transfer.”

Lippincott-Schwartz’s talk will touch on some of the advanced super-resolution imaging techniques and cutting-edge fluorescence-based technologies used in her lab, in conjunction with biochemistry, in vitro reconstitution, and computational biology, to answer pressing questions about cell structure.
Gia Voeltz of the University of Colorado, Boulder will talk about the ways in which endoplasmic reticulum (ER) orchestrates cell structure in her presentation, “The Role of ER Membrane Contact Sites in Regulating the Structure of Other Organelles.”

“Our lab is interested in understanding the molecular mechanisms that regulate the complex structure and function of the ER,” Voeltz explains on her laboratory mission statement. “The ER is highly dynamic and we have become increasingly interested in identifying the machinery that facilitates these dynamics. From a broader point of view, it is particularly intriguing to think about the cellular importance of ER structure and dynamics. Recently we have begun to address this through the identification of new roles for the ER at inter-organelle contact sites, which have portrayed the ER as a ‘master regulator’ within the cell. Through these studies, we aim to elucidate the complex interplay between ER biogenesis and its function at the cellular level.”

Mary Spiro

Mary Spiro has been ASCB's Science Writer and Social Media Manager since January 2017. She's the former science writer for Johns Hopkins Institute for NanoBioTechnology and writer/editor for University of Maryland Baltimore, LifeBridge Health and The Manhattan (KS) Mercury newspaper. She holds an MS in Biotechnology from Johns Hopkins University and bachelor's degrees in journalism and agronomy from the University of Maryland, College Park.