Posts Tagged ‘cell biology’

Powerful New Tool for Studying DNA Elements that Regulate Genes

 :: Posted by American Biotechnologist on 03-24-2014

An international team led by researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) has developed a new technique for identifying gene enhancers – sequences of DNA that act to amplify the expression of a specific gene – in the genomes of humans and other mammals. Called SIF-seq, for site-specific integration fluorescence-activated cell sorting followed by sequencing, this new technique complements existing genomic tools, such as ChIP-seq (chromatin immunoprecipitation followed by sequencing), and offers some additional benefits.

“While ChIP-seq is very powerful in that it can query an entire genome for characteristics associated with enhancer activity in a single experiment, it can fail to identify some enhancers and identify some sites as being enhancers when they really aren’t,” says Diane Dickel, a geneticist with Berkeley Lab’s Genomics Division and member of the SIF-seq development team. “SIF-seq is currently capable of testing only hundreds to a few thousand sites for enhancer activity in a single experiment, but can determine enhancer activity more accurately than ChIP-seq and is therefore a very good validation assay for assessing ChIP-seq results.”

Dickel is the lead author of a paper in Nature Methods describing this new technique. The paper is titled “Function-based identification of mammalian enhancers using site-specific integration.”

Read more…

Animal Cells Can Communicate by Reaching Out and Touching

 :: Posted by American Biotechnologist on 01-02-2014

In a finding that directly contradicts the standard biological model of animal cell communication, UCSF scientists have discovered that typical cells in animals have the ability to transmit and receive biological signals by making physical contact with each other, even at long distance.

The mechanism is similar to the way neurons communicate with other cells, and contrasts the standard understanding that non-neuronal cells “basically spit out signaling proteins into extracellular fluid and hope they find the right target,” said senior investigator Thomas B. Kornberg, PhD, a professor of biochemistry with the UCSF Cardiovascular Research Institute.

The paper was published on January 2, 2014 in Science.

Read more…

Regulating Cellular Trafficking

 :: Posted by American Biotechnologist on 09-23-2013

Molecular microbiologists at the University of Southern California (USC) have uncovered intricate regulatory mechanisms within the cell that could lead to novel therapeutics for the treatment of cancer and other diseases. Their findings, which have long-standing significance in the basic understanding of cell biology, appear in the journal Nature Cell Biology.

“Our research reveals a new regulatory mechanism that coordinates two distinct intracellular processes that are critical to cellular homeostasis and disease development,” said Chengyu Liang, M.D., Ph.D., a member of the USC Norris Comprehensive Cancer Center and principal investigator of the study.

The endoplasmic reticulum (ER) and Golgi apparatus are cellular organelles in eurkaryotic organisms where proteins are synthesized and packaged for secretion through the body. The trafficking of proteins between the ER and Golgi must be tightly modulated to maintain the health of the cell and prevent diseases like cancer from taking hold.

“Interest in the role of ER-Golgi network during cancer cell death has been gaining momentum,” said Shanshan He, Ph.D., research associate at the Keck School of Medicine of USC and one of the study’s first authors. “In this study, we identified a novel regulatory factor for the Golgi-ER retrograde transport and a new mechanistic connection between the physiological trafficking and the autophagic transportation of cellular material.”

The researchers discovered that the UV irradiation resistance-associated gene protein (UVRAG), which has been implicated in the suppression of colon and breast cancer, coordinates trafficking of proteins between the ER and Golgi apparatus and also autophagy, the natural process of breaking down cellular components.

“Given that the ER-Golgi network is often dismantled in malignant conditions and that UVRAG is intensively involved in different types of human cancers, this study gives us a new avenue to investigate anti-cancer agents that target UVRAG and/or the ER-Golgi pathway in cancer and other relevant diseases,” Liang said.

Source: University of Southern California – Health Sciences. “Protein identified that regulates cellular trafficking, potential for anti-cancer therapy.” ScienceDaily, 22 Sep. 2013. Web. 24 Sep. 2013.

New method of endocrine signaling discovered

 :: Posted by American Biotechnologist on 02-06-2013

Cells communicate in many ways. The can communicate through direct contact (juxtacrine signaling), over short distances (paracrine signaling), or over large distances (endocrine signaling). Until now, endocrine signaling research has focused primarily on hormones which can transverse relatively large distances in order to convey their message to target cells. Now, scientists at UCLA have discovered a previously unknown method of long distance cell-to-cell communication that does not involve the use of hormones.

In a study published in the American Journal of Translational Research, Dr. Keith Norris, senior author of the research and assistant dean for clinical and translational science at the David Geffen School of Medicine at UCLA, and his team found that cells located on the inside of a hormonally impervious membrane were able to receive messages regulating their calcium signaling pathways from cells located outside the membrane.

Click here to read the full story.

Is Deformation the New Transformation?

 :: Posted by American Biotechnologist on 01-23-2013

Researchers from MIT have now found a safe and efficient way to get large molecules through the cell membrane, by squeezing the cells through a narrow constriction that opens up tiny, temporary holes in the membrane. Any large molecules floating outside the cell — such as RNA, proteins or nanoparticles — can slide through the membrane during this disruption.

Click here to read the full story…