Ferroptosis – and the way to inhibit it

A lot of compounds are known and available to modulate (inhibit or activate) the most prominent mode of programmed cell death – Apoptosis. In a recent post, I summarized methods to detect early Apoptosis and at the end of this post you’ll find a list of apoptosis modulators (available through tebu-bio). But there are other modes of programmed cell death, such as Autophagy (see How to manipulate and measure Autophagy), Necroptosis, and Ferroptosis.

Today I would like to focus on Ferroptosis, and invite you to take a look at the first Ferroptosis inhibitor on the market. [Read more…]

Detect different isoforms of Rho, Ras and Rac

small-g-protein-inactivationRas and Rho family members are small G proteins involved in the regulation of actin-dependent cell processes such as motility, growth, and intracellular trafficking. Furthermore, dysfunctions of Ras and Rho proteins are known to be correlated with a number of diseases (cancer, neurodegeneration).

Small G proteins cycle between the inactive, GDP-bound form and the active, GTP-bound form.

G-LISA technology: state of the art small G protein activation measurement

Cytoskeleton, Inc. offers activation kits for a number of small G proteins (RhoA, Rac1, Cdc42, Ras, RalA, Arf1, Arf6). All these assays are available as G-LISA formats, a 96 well based technology, in which a protein sequence specifically binding to the activated for of the respective small G protein is coupled to the bottom of the wells and “catches” activated, GTP-bound proteins from cell lysates derived from cultured cells. The activation status of the small G protein can thus be detected in an ELISA like, quantitative approach.

A number of recently published papers using Cytoskeleton’s G-LISA kits show that not only RhoA and Rac1 can be measured with the RhoA-G-LISA and Rac1 G-LISA, respectively. By changing the antibody which is finally used to detect the activated small G protein bound to the binding protein one can e.g. differentiate between the isoforms RhoA, RhoB, and RhoC, and even RhoJ (which shows a high homology with Cdc42).

In their November newsletter Cytoskeleton Inc. summarized these publications and give valuable information and tips how to broaden the target specificity of their G-LISA kits.

Download your free copy of the newsletter GTPase Activation Assays: Detecting Different Isoforms

Any questions about using G-LISA? Fire away below!

New hope for Ras inhibitors

Ras belongs to the family of small G-proteins and plays an important role in several signal transduction pathways involved in normal cell growth and differentiation. Over 30 years ago three isoforms of Ras – H-Ras, N-Ras, and K-Ras, have been identified for their oncogenic activation in human cancer cells. In fact aberrant Ras signaling could be shown in more than 30% of all human cancers including lung, colon, and pancreatic cancer. K-Ras has been identified as the most important Ras protein in cancer research.

As other small G proteins, Ras cycles between inactive (GDP-bound) and active state (GTP-bound) forms (see figure).

Ras and Inhibitors

Although extensive research activities have been dedicated to Ras, no effective Ras inhibitor has been identified so far. But, there may be new hope in developing a therapeutic inhibitor to Ras proteins by targeting the upstream guanine nucleotide exchange factor (GEF) protein SOS (Son of sevenless). [Read more…]