High-performance microscope reveals unique pores in cell nucleus. Nuclear pores are one of largest and most intricate structures present in cell, comprising of more than 200 distinctive proteins arranged in a ring-like formation.
A research team from UZH, headed by Professor Ohad Medalia, has for the first time successfully displayed the spatial structure of certain unique transport channels within the pores of the cell’s nucleus. Using high-performance microscopy, the researchers were able to visualize these distinct molecular gateways with more precision in high resolution.
Structure Of Nuclear Pores
An active exchange of materials between the cytoplasm and the nucleus is continuously taking place inside the cell. In humans, more than a million different molecules are transported in the nucleus in only a minute. This exchange is facilitated by the presence of special pores embedded in the nuclear membrane.
Nuclear pores are one of the largest and most intricate structures present in the cell, comprising of more than 200 distinctive proteins arranged in a ring-like formation. They have a diameter of a ten thousandth of a millimeter. These pores act as ‘transport gates’, allowing small materials to pass through unobstructed, while inhibiting certain larger ones that might cause damage.
Novel Discovery – ‘Molecular Gate’ In Nuclear Pores
The researchers used cryo-electron microscopes to visualize the nuclear pores of shock-frozen specimens of clawed frog oocytes. The team was able to display the structure of the minute pores with greater precision and in a higher resolution than ever before. This allowed them to discover the presence of many new structures and previously undiscovered details.
“We discovered a previously unobserved structure inside the nuclear pore that forms a kind of molecular gate, which can only be opened by molecules that hold the right key,” reported Medalia.
This molecular gate, or so-called ‘spoke ring’, was found to be sandwiched between two more rings, with the entire structure extending inside the pores of the nucleus. The configuration of the gate itself was that of a fine lattice, enabling molecules of a low molecular weight to pass through it uninhibited.
Advantages Of Finding
This discovery of a novel molecular gateway within the nuclear pores could lead to an improved understanding of the precise mechanisms of exchanges that take place between the nucleus and cytoplasm. Knowing exactly why certain compounds are granted entry and some are turned away could help scientists understand the development of diseases associated with defective transportation channels within the nucleus – ovarian, intestinal and thyroid cancer being potent examples.