Featured Research

from universities, journals, and other organizations

Ovastacin cuts off sperm binding

Date:
April 2, 2012
Source:
Rockefeller University Press
Summary:
A new study describes how a secreted enzyme helps egg cells avoid being fertilized by more than one sperm.

A study in the Journal of Cell Biology describes how ovastacin helps egg cells avoid being fertilized by more than one sperm. In this image, ovastacin (red) localizes to secretory granules (green) in the cortex of an unfertilized egg.
Credit: Burkart, A.D., et al. 2012. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201112094.

Researchers have described how a secreted protease helps egg cells avoid being fertilized by more than one sperm.

Because polyspermy disrupts embryonic development, oocytes take several steps to ensure they only fuse with a single sperm. One key step is to prevent additional sperm from binding to the surface of an already-fertilized egg, a blockade that involves the release of secretory granules and cleavage of the glycoprotein ZP2, a component of the zona pellucida matrix that surrounds eggs. ZP2 is cleaved upstream of two acidic amino acids, a cleavage site recognized by the astacin family of metalloendoproteases. Burkart et al. therefore investigated the function of ovastacin, an astacin family member expressed in oocytes.

Ovastacin localized to cortical granules that were exocytosed after fertilization, and recombinant ovastacin cleaved ZP2 when added to zonae pellucidae. Mice lacking ovastacin failed to cleave ZP2 after fertilization, allowing sperm to continue to bind to the surface of early embryos. Ovastacin-null female mice had slightly fewer offspring than wild-type animals but otherwise appeared normal.

The researchers found that ovastacin targeted several sites in ZP2's N terminus. Senior author Jurrien Dean now wants to investigate how this proteolysis blocks sperm binding, a critical question because the molecular interactions between sperm and egg cells remain unknown. He also wants to examine how ovastacin is packaged into oocyte cortical granules and to identify other components of these secretory organelles.


Story Source:

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


Journal Reference:

  1. A. D. Burkart, B. Xiong, B. Baibakov, M. Jimenez-Movilla, J. Dean. Ovastacin, a cortical granule protease, cleaves ZP2 in the zona pellucida to prevent polyspermy. The Journal of Cell Biology, 2012; 197 (1): 37 DOI: 10.1083/jcb.201112094

Cite This Page:

Rockefeller University Press. "Ovastacin cuts off sperm binding." ScienceDaily. ScienceDaily, 2 April 2012. <www.sciencedaily.com/releases/2012/04/120402124335.htm>.
Rockefeller University Press. (2012, April 2). Ovastacin cuts off sperm binding. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2012/04/120402124335.htm
Rockefeller University Press. "Ovastacin cuts off sperm binding." ScienceDaily. www.sciencedaily.com/releases/2012/04/120402124335.htm (accessed September 2, 2014).

Share This




More Health & Medicine News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 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