Featured Research

from universities, journals, and other organizations

Endoplasmic reticulum: Scientists image 'parking garage' helix structure in protein-making factory

Date:
July 18, 2013
Source:
Cell Press
Summary:
The endoplasmic reticulum is the protein-making factory within cells consisting of tightly stacked sheets of membrane studded with the molecules that make proteins. Now, researchers have refined a new microscopy imaging method to visualize exactly how the ER sheets are stacked, revealing that the 3D structure of the sheets resembles a parking garage. This structure allows for the dense packing of ER sheets, maximizing the amount of space available for protein synthesis.

The endoplasmic reticulum (ER) is the protein-making factory within cells consisting of tightly stacked sheets of membrane studded with the molecules that make proteins. In a study published July 18th by Cell Press in the journal Cell, researchers have refined a new microscopy imaging method to visualize exactly how the ER sheets are stacked, revealing that the 3D structure of the sheets resembles a parking garage with helical ramps connecting the different levels. This structure allows for the dense packing of ER sheets, maximizing the amount of space available for protein synthesis within the small confines of a cell.
Credit: Cell, Terasaki et al.

The endoplasmic reticulum (ER) is the protein-making factory within cells consisting of tightly stacked sheets of membrane studded with the molecules that make proteins. In a study published July 18th by Cell Press in the journal Cell, researchers have refined a new microscopy imaging method to visualize exactly how the ER sheets are stacked, revealing that the 3D structure of the sheets resembles a parking garage with helical ramps connecting the different levels. This structure allows for the dense packing of ER sheets, maximizing the amount of space available for protein synthesis within the small confines of a cell.

"The geometry of the ER is so complex that its details have never been fully described, even now, 60 years after its discovery," says study author Mark Terasaki of the University of Connecticut Health Center. "Our findings are likely to lead to new insights into the functioning of this important organelle."

Jeff Lichtman and colleagues at Harvard developed an improved technique for staining ER membrane sheets that allowed them to visualize the 3D structure in unprecedented detail. Applying this new scanning electron microscopy method to mouse neurons and salivary gland cells, Terasaki and his colleague Art Hand, along with Tom Rapoport of Harvard Medical School, discovered that ER sheets form a continuous membrane system consisting of stacked levels connected by a well-known geometric shape called the helicoid, which resembles a spiral staircase.

Moreover, a theoretical model developed by collaborators Michael Kozlov and Tom Shemesh revealed that this "parking garage" structure optimizes the dense packing of ER sheets and thus maximizes the number of protein-synthesizing molecules called ribosomes within the restricted space of a cell. When a cell needs to secrete more proteins, it can reduce the distances between sheets to pack even more membrane into the same space. Think of it as a parking garage that can add more levels as it gets full. "The theory explains that this structure is seen in nature because it maximizes the cell's ability to make a large number of proteins while minimizing the energetic cost to the cell," Rapoport says. "The paper is an excellent example for the role that theory can play in biology."


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mark Terasaki, Tom Shemesh, Narayanan Kasthuri, RobinW. Klemm, Richard Schalek, KennethJ. Hayworth, ArthurR. Hand, Maya Yankova, Greg Huber, JeffW. Lichtman, TomA. Rapoport, MichaelM. Kozlov. Stacked Endoplasmic Reticulum Sheets Are Connected by Helicoidal Membrane Motifs. Cell, 2013; 154 (2): 285 DOI: 10.1016/j.cell.2013.06.031

Cite This Page:

Cell Press. "Endoplasmic reticulum: Scientists image 'parking garage' helix structure in protein-making factory." ScienceDaily. ScienceDaily, 18 July 2013. <www.sciencedaily.com/releases/2013/07/130718130617.htm>.
Cell Press. (2013, July 18). Endoplasmic reticulum: Scientists image 'parking garage' helix structure in protein-making factory. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2013/07/130718130617.htm
Cell Press. "Endoplasmic reticulum: Scientists image 'parking garage' helix structure in protein-making factory." ScienceDaily. www.sciencedaily.com/releases/2013/07/130718130617.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Peace Corps Pulls Workers From W. Africa Over Ebola Fears

Newsy (July 30, 2014) The Peace Corps is one of several U.S.-based organizations to pull workers out of West Africa because of the Ebola outbreak. Video provided by Newsy
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins