Navigation Links
Gatekeeping: Penn researchers find new way to open ion channels in cell membranes

Using an enzyme found in the venom of the brown recluse spider, researchers at the University of Pennsylvania School of Medicine have discovered a new way to open molecular pores, called ion channels, in the membrane of cells. The research team ?Zhe Lu, MD, PhD; Yajamana Ramu, PhD; and Yanping Xu, MD, PhD of the Department of Physiology at Penn ?screened venoms from over 100 poisonous invertebrate species to make this discovery.

The enzyme, sphingomyelinase D (SMase D), splits a lipid called sphingomyelin that surrounds the channel embedded in the cell membrane. As a result, the channel opens to allow the passage of small ions into and out of the cell, thereby generating electrical currents.

The new study, published online earlier this month in the journal Nature, describes how SMase D opens one type of ion channel called a voltage-gated potassium channel (from brain, but experimentally expressed in the membrane of an oocyte, or egg cell) without changing the membrane voltage. The finding introduces a new paradigm for understanding the gating of ion channels and lays the conceptual groundwork for designing new drugs to control ion-channel activity in medical intervention.

Voltage-gated ion channels are embedded in the cell membranes of most types of cells. It has been known for over half a century that the channels open and close in response to changes in electric voltage across the cell membrane, hence their name. In some the cells, (commonly called "excitable"), such as nerve, muscle, heart, and hormone-secreting cells, the channels underlie electrical signaling. They selectively allow the passage of small ions such as sodium, potassium, or calcium into and out of the cell. The precisely controlled passage of ions generates the electrical currents that enable nerve impulse transmission, hormone secretion, and muscle contraction and relaxation. When there are changes to the channel, such as by mutations in a channel gene, disease can re sult. For example, mutations in some channel genes cause cardiac arrhythmias, including a form of the lethal long QT syndrome.

Voltage-gated ion channels are also present in the so-called non-excitable cells (such as immune, blood, and bone cells) whose membrane voltage stays largely constant, as opposed to the excitable cells whose membrane voltage constantly varies in a precisely controlled manner. How the activity of channels in non-excitable cells is regulated has been a long-standing biological mystery. This new finding that SMase D can open ion channels without changing membrane voltage provides a clue to the mystery.


'"/>

Source:University of Pennsylvania School of Medicine


Related biology news :

1. NYU researchers simulate molecular biological clock
2. Vital step in cellular migration described by UCSD medical researchers
3. ASU researchers finds novel chemistry at work to provide parrots vibrant red colors
4. UCSD researchers maintain stem cells without contaminated animal feeder layers
5. Why do insects stop breathing? To avoid damage from too much oxygen, say researchers
6. New protein discovered by Hebrew University researchers
7. First real-time view of developing neurons reveals surprises, say Stanford researchers
8. Agilent Technologies releases automated literature search tool for biology researchers
9. Self-assembled nano-sized probes allow Penn researchers to see tumors through flesh and skin
10. Yale researchers identify molecule for detecting parasitic infection in humans
11. US life expectancy about to decline, researchers say
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:1/11/2017)... 11, 2017  Michael Johnson, co-founder of Visikol Inc. a company ... has been named to the elite "Forbes 30 Under 30" list ... 600 people in 20 fields nationwide to be recognized as a ... applicants were selected. ... He is currently a PhD candidate at Rutgers University. ...
(Date:1/6/2017)... 5, 2017  Delta ID Inc., a leader in ... for automotive at CES® 2017. Delta ID has collaborated ... demonstrate the use of iris scanning as a secure, ... driver in a car, and as a way to ... Delta ID and Gentex will demonstrate (booth ...
(Date:1/3/2017)... Onitor, provider of digital health technology for ... innovative biometric data-driven program designed to aid weight loss ... 2017 Consumer Electronics Show (CES) in Las ... the World Health Organization (WHO), have identified lifestyle risks ... are overweight or obese. WHO also states that more ...
Breaking Biology News(10 mins):
(Date:1/18/2017)... ... 2017 , ... MYOLYN, which creates medical technology for people ... to the FDA, requesting clearance of the MyoCycle Home and the MyoCycle Pro ... , The submission marks a major milestone for the technology startup. MYOLYN spun ...
(Date:1/18/2017)... , ... January 18, 2017 , ... ... publishing of the latest paper by its Science Editor, Dr. Elisabeth Bik, in ... voor Medische Microbiologie). Dr. Bik joined uBiome in October 2016 from her previous ...
(Date:1/18/2017)...  Caris Life Sciences, a leading innovator in ... private funder of pancreatic cancer research, are collaborating ... of immunotherapy in the treatment of pancreatic cancer. ... identify potential trial candidates based on biomarker expression ... study investigators. The Lustgarten Foundation is a sponsor ...
(Date:1/17/2017)... ... January 17, 2017 , ... MS Technologies™ and Bayer ... GT Soybean Performance System will combine industry-leading genetics with a double herbicide-tolerant trait ... new Balance® Bean herbicide. The Balance™ GT Soybean Performance System will benefit soybean ...
Breaking Biology Technology: