DAVID GRANOVSKY

Posts Tagged ‘scripps’

TZAP! GOES THE TELOMERE FUSE

In DISEASE INFO, HEALTH AND WELLNESS, OFF THE BEATEN PATH, PHARMA AND DRUGS, SCIENCE & STEM CELLS on January 21, 2017 at 9:44 am

burning-cancle-both-emds

EVERY TIME A CELL DIVIDES, A TELOMERE LOSES IT’S WINGS

  • The length of a telomere controls cell age.
  • Each time a cell splits, the telomere gets smaller.
  • Too long and cancer risk increases.
  • Too short and no more cell division.

Scripps Research Institute discovered the TZAP that controls telomere length.  “TZAP: a Telomere-Associated Protein involved in telomere length control”

Master regulator of cellular aging discovered

Date: January 12, 2017 – Source: Scripps Research Institute – Summary: Scientists have discovered a protein that fine-tunes the cellular clock involved in aging.
Cell culture under microscope (stock image).
Credit: © sinitar / Fotolia
 Scientists at The Scripps Research Institute (TSRI) have discovered a protein that fine-tunes the cellular clock involved in aging.

This novel protein, named TZAP, binds the ends of chromosomes and determines how long telomeres, the segments of DNA that protect chromosome ends, can be. Understanding telomere length is crucial because telomeres set the lifespan of cells in the body, dictating critical processes such as aging and the incidence of cancer.

“Telomeres represent the clock of a cell,” said TSRI Associate Professor Eros Lazzerini Denchi, corresponding author of the new study, published online today in the journal Science. “You are born with telomeres of a certain length, and every time a cell divides, it loses a little bit of the telomere. Once the telomere is too short, the cell cannot divide anymore.”

Naturally, researchers are curious whether lengthening telomeres could slow aging, and many scientists have looked into using a specialized enzyme called telomerase to “fine-tune” the biological clock. One drawback they’ve discovered is that unnaturally long telomeres are a risk factor in developing cancer.

“This cellular clock needs to be finely tuned to allow sufficient cell divisions to develop differentiated tissues and maintain renewable tissues in our body and, at the same time, to limit the proliferation of cancerous cells,” said Lazzerini Denchi.

In this new study, the researcher found that TZAP controls a process called telomere trimming, ensuring that telomeres do not become too long.

“This protein sets the upper limit of telomere length,” explained Lazzerini Denchi. “This allows cells to proliferate — but not too much.”

For the last few decades, the only proteins known to specifically bind telomeres is the telomerase enzyme and a protein complex known as the Shelterin complex. The discovery TZAP, which binds specifically to telomeres, was a surprise since many scientists in the field believed there were no additional proteins binding to telomeres.

“There is a protein complex that was found to localize specifically at chromosome ends, but since its discovery, no protein has been shown to specifically localize to telomeres,” said study first author Julia Su Zhou Li, a graduate student in the Lazzerini Denchi lab.

“This study opens up a lot of new and exciting questions,” said Lazzerini Denchi.

In addition to Lazzerini Denchi and Li, authors of the study, “TZAP: a telomere-associated protein involved in telomere length control,” were Tatevik Simavorian, Cristina Bartocci and Jill Tsai of TSRI; Javier Miralles Fuste of the Salk Institute for Biological Studies and the University of Gothenburg; and Jan Karlseder of the Salk Institute for Biological Studies.

The study was supported by the American Cancer Society (grant RSG-14-186-01), the Swedish Research Council International (grant D0730801) and the National Institutes of Health (grant R01GM087476 and R01CA174942).


Story Source:

Materials provided by Scripps Research Institute. Note: Content may be edited for style and length.


Journal Reference:

  1. Julia Su Zhou Li, Javier Miralles Fuste, Tatevik Simavorian, Cristina Bartocci, Jill Tsai, Jan Karlseder, Eros Lazzerini Denchi. TZAP: A telomere-associated protein involved in telomere length control. Science, 2017; DOI: 10.1126/science.aah6752

Groundbreaking New Understanding of Stem Cells: Findings May Improve Ability to Manipulate Cell Fate and Promote Healing | www.sciencemagnews.com

In SCIENCE & STEM CELLS on May 21, 2010 at 5:52 pm

Groundbreaking New Understanding of Stem Cells: Findings May Improve Ability to Manipulate Cell Fate and Promote Healing

The study, led by Scripps Research Associate Professor Sheng Ding and Senior Director of the Scripps Research Center for Mass Spectrometry Gary Siuzdak, was published in an advance, online edition of the journal Nature Chemical Biology on May 2, 2010.

In the research, the team used a unique approach to better understand stem cells, which have the ability to change or “differentiate” into adult cell types such as hair cells, skin cells, nerve cells. Understanding how stem cells mature opens the door for scientists and physicians to manipulate the process to meet the needs of patients, potentially treating such intractable conditions as Parkinson’s disease and spinal injury.”In the past, scientists trying to understand stem cell biology focused on genes and proteins,” said Ding. “In our study, we looked at stem cell regulation in a different way — on the biochemical level, on a functional level. With metabolomics profiling, we were able to look at naturally occurring small molecules and how they control cell fate on a completely different level.”The new paper describes parts of the stem cell “metabolome” — the complete set of substances “metabolites” formed in metabolism, including all naturally occurring small molecules, biofluids, and tissues. The scientists then compared this profile to those of more mature cells, specifically of nerve cells and heart cells.When the results were tallied, the scientists had found about 60 previously unidentified metabolites associated with the progression of stem cells to mature cells, as well as an unexpected pattern in the chemistry that mirrored the cells’ increasing biological maturity.

via Groundbreaking New Understanding of Stem Cells: Findings May Improve Ability to Manipulate Cell Fate and Promote Healing | www.sciencemagnews.com.

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