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: High-performance microscope displays pores in the cell nucleus with greater precision

Related Stories

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 ...

Blueprints for the construction of nuclear pores deciphered

May 6, 2015

In a recent study, a team of researchers led by Alwin Köhler at the Max F. Perutz Laboratories (MFPL) belonging to the University of Vienna and the Medical University of Vienna offer new insights into how nuclear pores are ...

Study shows where damaged DNA goes for repair

May 3, 2015

A Tufts University study sheds new light on the process by which DNA repair occurs within the cell. In research published in the May 15 edition of the journal Genes & Development and available May 4 online in advance of print, ...

Recommended for you

Magnetism at nanoscale

August 3, 2015

As the demand grows for ever smaller, smarter electronics, so does the demand for understanding materials' behavior at ever smaller scales. Physicists at the U.S. Department of Energy's Ames Laboratory are building a unique ...

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Study calculates the speed of ice formation

August 3, 2015

Researchers at Princeton University have for the first time directly calculated the rate at which water crystallizes into ice in a realistic computer model of water molecules. The simulations, which were carried out on supercomputers, ...

Small tilt in magnets makes them viable memory chips

August 3, 2015

University of California, Berkeley, researchers have discovered a new way to switch the polarization of nanomagnets, paving the way for high-density storage to move from hard disks onto integrated circuits.

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.