New model of a nuclear pore complex is based on crystal structure of its key component

January 16, 2008

Everything that goes in and out of a cell’s nucleus must pass through one of its nuclear pores. In the second nuclear pore study to come out of Rockefeller University in as many months, researchers have determined the crystal structure of one of the pore’s main components and used it to propose an overall structure for the circular pore, rings of alternating protein complexes that fit together like two sides of a zipper.

In research published in the journal Cell, a team of scientists from Günter Blobel’s Laboratory of Cell Biology describes how they crystallized a central component of the nuclear pore that provided a tantalizing glimpse of the pore’s structure in its entirety. Building on this component, the team has proposed a new molecular model of the nuclear pore.

Visualizing the nuclear pore complex is a particularly tricky endeavor: It’s such a large, pliant structure that traditional methods just don’t work. So researchers have had to get creative. Just a month ago, two Rockefeller professors published the first complete model of a nuclear pore complex created through a combination of biochemical, spectrometry and computer-modeling techniques. Blobel’s team — Kuo-Chiang Hsia, Peter Stavropoulos, Blobel and André Hoelz — used an approach that was quite different: x-ray crystallography to visualize a core piece of the pore and determine how it bound to a neighboring complex, then puzzle-solving to deduce how the rest of the structure fit together. In the end, the researchers’ results differed, too. But the new findings were consistent with research published by the Blobel lab last spring, which proposed a ring-like arrangement of sliding subunits.

Using the high-resolution structures they’ve uncovered, Hoelz says, the lab is working to build a model of the nuclear pore complex that’s constructed piece by piece. He and Blobel found that their complex — called Sec13-Nup145C — crystallized into two distinct shapes that came together to form a bent rod. From there, they devised a molecular architecture for the pore that consists of eight of these rods, placed vertically, linking four stacked rings of alternating protein complexes in a pattern akin to houndstooth. Hoelz, a research associate, and Blobel, John D. Rockefeller Jr. Professor and a Howard Hughes Medical Institute investigator, propose that this structure may represent one of the four concentric cylinders that, according to their previous research, may make up the core of the nuclear pore. “Clearly more work will be required to test these two proposals,” Blobel says.

The nuclear pore is the center of so much attention because everything that goes in and out of the nucleus has to pass through. But apart from a few binding sites, “the structure is essentially a black box,” Hoelz says. “And if we don’t know how it looks and how it is constructed in atomic detail, then we have no way to figure out how this large transport machine works.”

Citation: Cell 131(7): 1313–1326 (December 28, 2007)

Source: Rockefeller University

Explore further: Chemists solve major piece of cellular mystery

Related Stories

Chemists solve major piece of cellular mystery

August 27, 2015

Not just anything is allowed to enter the nucleus, the heart of eukaryotic cells where, among other things, genetic information is stored. A double membrane, called the nuclear envelope, serves as a wall, protecting the contents ...

Protein plays unexpected role in embryonic stem cells

June 18, 2015

What if you found out that pieces of your front door were occasionally flying off the door frame to carry out chores around the house? That's the kind of surprise scientists at the Salk Institute experienced with their recent ...

Dissecting the brain's primary developmental engine

September 18, 2013

(Phys.org) —Last month, researchers reported the creation of the first primitive brain-like structures made from human stem cells. To create the complex morphology of these cerebral organoids, cells within a proliferating ...

Recommended for you

New nanomaterial maintains conductivity in 3-D

September 4, 2015

An international team of scientists has developed what may be the first one-step process for making seamless carbon-based nanomaterials that possess superior thermal, electrical and mechanical properties in three dimensions.

Secrets of a heat-loving microbe unlocked

September 4, 2015

Scientists studying how a heat-loving microbe transfers its DNA from one generation to the next say it could further our understanding of an extraordinary superbug.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.