Navigation Links
New Way to Open Cellular Ion Channels, Implications for Drug Design

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 chan nel gene, disease can result. 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: Newswise
'"/>




Related medicine news :

1. Use of Cellular Phones associated with Increased risk of Brain Tumors
2. Researchers Discover Two Proteins Involved In Cellular Destruction Of HIV Virus
3. Unchecked Cellular Repair Pathway Causes Liver Cancer
4. Cellular System Causing Destruction Of Faulty Proteins In Cystic Fibrosis Identified
5. Gene May Regulate Cellular Aging
6. Cellular Cues Identified for Stroke Recovery
7. Cellular Pathway Yields Potential New Weapon in Vaccine Arsenal
8. Cocaines Use During Pregnancy May Cause Lasting Cellular Effects
9. Genetic Eye Disorder Can Have Other Implications
10. Implications of Statin Therapy in Bladder Cancer Patients
11. First Vaccine Designed for Africa Cleared for Testing in Humans
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:12/8/2016)... ... December 08, 2016 , ... Coppin Insurance Agency, an insurance and financial planning ... the Cape Coral area, is embarking on a charity drive with the goal of ... The Harry Chapin Food Bank of Southwest Florida works to provide fresh and nutritious ...
(Date:12/8/2016)... ... December 08, 2016 , ... Bill Mull Agencies, a ... in and around central Kansas, is joining the Youth Horizons organization for a ... , Headquartered in Wichita, Youth Horizons works to empower area children from unstable, ...
(Date:12/7/2016)... ... December 07, 2016 , ... "Today, MHA and mental ... mental health systems reform legislation in more than fifty years. We applaud the ... of our elected officials to improving mental health services and supports in our ...
(Date:12/7/2016)... ... December 07, 2016 , ... Silhouette Instalift is a ... smoothing and tightening the skin of the face to create more youthful features. ... with very little downtime, Silhouette Instalift is a novel, minimally invasive facial procedure ...
(Date:12/7/2016)... ... December 07, 2016 , ... ... Technology, S.L. (“Presence”) for a purchase price of approximately $17.4 million (net ... Presence’s annual revenue is approximately $13.2 million. Headquartered in Barcelona, Spain, Presence ...
Breaking Medicine News(10 mins):
(Date:12/8/2016)... de dezembro de 2016  A Mederi Therapeutics Inc . anunciou aprovação ... não cirúrgico para a doença do refluxo gastroesofágico (DRGE). Foto -  ... ... Live Stretta procedure performed and broadcast during the Chinese ... Union Hospital , ...
(Date:12/8/2016)... , Dec. 8, 2016 Bodycad announced ... for improving the accuracy, reproducibility and speed for ... long and small bone orthopaedic applications. These patents ... creating personalized orthopaedic restorations based on each patient,s ... restorations, the company harnesses the world,s first suite ...
(Date:12/8/2016)... , Dec. 8, 2016  Valeant Pharmaceuticals International, ... VRX) ("Valeant") today announced positive results from a ... to assess the safety and efficacy of IDP-118 ... of plaque psoriasis. Within the ... moderate to severe psoriasis, IDP-118 showed statistical significance ...
Breaking Medicine Technology: