Tiny and seemingly simple organelles can cause big problems for an organism, if they get out of control. The centrosome, composed of just two barrel-shaped centrioles and a mass of proteins in human cells, forms the microtubule organizing center that regulates cell division (cytokinesis). During cell division, two centrosomes at opposite poles of the cell work together to position the mitotic spindle. An increase in the number of centrosomes is "a hallmark of human tumors," according to Véronique Marthiens and Renata Basto at the Curie Institute in Paris who report in Nature Cell Biology on their surprising results in mice after adding extra centrosomes in the cells of the developing central nervous system (CNS).
RNA interference (RNAi) is a Nobel Prize-winning discovery first published in 1998 by Andrew Fire and Craig Mello. The potential of RNAi technology to silence genes involved in disease was apparent from the beginning, at least in theory. These theoretical RNAi therapies would switch off genes upregulated in diseased cells, such as in cancer or Huntington's disease. However, delivering RNAi treatments to deep tissues within the body posed enormous challenges until now.
A foundation created by a Slovakian-born microbiologist who helped shape a monoclonal antibody into a clinically effective tumor necrosis factor (TNF) blocker will once again award three $35,000 no-strings cash prizes to young immigrant scientists who demonstrate "exceptional" records of early career achievement in the life sciences.
The year 1953 is generally considered the year zero for molecular cell biology with the publication of Watson and Crick's celebrated Nature paper on the structure of DNA. But there was another big paper in 1953 by Yves Clermont and Charles Leblond of McGill University that appeared in the American Journal of Anatomy.
With the death from brain cancer of Senator Ted Kennedy in 2009, gliobastoma multiforme (GBM), made a brief but frightening appearance in the news. GBM is a bitter diagnosis with a poor prognosis. More than half the patients will die within one year and the five-year survival rate is approximately 5%. Why is this cancer so deadly?
Actin's role in the nucleus comes packed in its very own black box. The cell nucleus is a very small and complex place but given how much is known about actin in the cytoplasm, it can be startling to hear how little agreement there is about actin in the nucleus.
The mad cow disease, or bovine spongiform encephalopathy (BSE), outbreak that burst into the news in the United Kingdom in the late 1980s is caused by a harmful version of the prion protein. In affected cows, the misfolded prion protein results in the degeneration of the nervous system and eventual death. Alarmingly, the incidence of the human version of BSE, known as Creutzfeld-Jakob Disease (CJD), increased following the bovine epidemic, indicating that the disease could transfer from one species to another. How the misfolded version of the prion protein causes these neurodegenerative diseases is currently not understood.
Proteins have to be transported through the complex internal environment of a cell to reach their site of function. Nowhere is this more evident than in brain cells, or neurons, which communicate with each other over long distances at specialized sites of contact, called synapses. Through a poorly understood process, the neuron must sort through thousands of protein to identify a small set of proteins that must travel to the synapse.
If you forgot to add the zip code to a letter, would it still reach the correct destination? Eventually it should, thanks to the US Postal Service and the other address information. Cells also need to ensure their messages reach the correct destinations, and a recent paper in Molecular Biology of the Cell reveals that, just like the post office, cells use multiple layers of information to target messenger RNA transcripts (mRNAs) to an important cellular address.
Every cell in the body starts off with essentially the same genome, but sometimes the DNA sequence in a cell gets changed. Some of these changes are due to normal physiology (e.g. DNA is rearranged in immune cells to generate diversity in the adaptive immune system), but others are actual errors that occur when the DNA is copied during cell base. Some mistakes involve the introduction of long sequences in which short DNA "words" are repeated many times. Like a skipping CD (or an old school vinyl record), small areas of the genome are repeated over and over again and once it's copied in the DNA, all subsequent cellular offspring, have the repeated mistake.