Pure Biology:
How are signal cascades built? And how can we decipher their inner workings? Alex van Oudenaarden shows how.
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Posted on May 11, 2008 12:14 PM • 3 Comments •
Here's a nice giant cell with gobs of ER.
Posted on April 14, 2008 6:35 PM • 0 Comments •
In the last part of this series we will head back to the role of metabolsm on how cells can proliferate. In the process we will cover two important papers published last month in Nature.
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Posted on April 2, 2008 11:35 AM • 6 Comments •
George Daley dicussed the results of that incredible Lin-28 paper on NPR's Talk of the Nation. Click here to listen....
Posted on March 25, 2008 11:24 AM • 1 Comments •
Ribosome synthesis and assembly occurs in the nucleolus. I snapped this micrograph in December '04.
Posted on March 25, 2008 8:36 AM • 3 Comments •
A new study links all these players up.
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Posted on March 24, 2008 5:05 PM • 11 Comments •
Today we'll go from Easter Island to the ribosome and back to oncogenes.
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Posted on March 21, 2008 8:56 AM • 2 Comments •
We'll start with the Warburg hypothesis, and end with Bishop and Varmus' discovery of
src.
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Posted on March 17, 2008 6:10 PM • 4 Comments •
How does the genomic output produce the substrate of life, and how does this promote evolvability.
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Posted on March 4, 2008 7:54 PM • 3 Comments •
Wilkins doesn't see the relevance - he should go talk to Craig Venter.
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Posted on February 25, 2008 9:27 PM • 4 Comments •
Do we reclaim the word "Design" from ID? Lets start with "machine".
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Posted on February 24, 2008 11:58 AM • 9 Comments •
How is a genotype converted into a phenotype.
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Posted on February 21, 2008 9:39 AM • 7 Comments •
I'm almost done with my grant. Yesterday I sent out a 95% completed version of my proposal to SPA (Sponsored Programs Administration - an organization that vets grants to make sure that there are no conflicts of interests and that...
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Posted on February 9, 2008 8:41 AM • 0 Comments •
About 1% of the genome is expressed as bits of ncRNA in the brain.
Posted on January 16, 2008 8:37 AM • 0 Comments •
Why is this finding important? What are the implications?
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Posted on December 29, 2007 9:45 AM • 1 Comments •
Since the discovery of IPS Cells, the stem cell field has exploded. Here's a few links on the latest developements.
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Posted on December 11, 2007 9:32 PM • 1 Comments •
It's true, you CAN blog and produce some original science!
Posted on December 4, 2007 2:37 PM • 16 Comments •
... and I'm not there. If there's anything noteworthy, please leave a comment.
Posted on December 2, 2007 9:34 AM • 9 Comments •
Wow! One of the biggest findings of the year! I'll have to read the article more carefully before I comment on it - previously, I wrote a post on the paper that led to this new discovery that was just...
Posted on December 1, 2007 5:26 PM • 5 Comments •
A new paradigm for one of the oldest enzymes.
Posted on November 29, 2007 8:36 AM • 0 Comments •
A fantastic advance for our understanding of how cells are reprogrammed that incidentally explodes some of the ideas on conception and the creation of "souls".
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Posted on November 21, 2007 9:05 AM • 11 Comments •
From last week's issue of Nature.
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Posted on November 7, 2007 9:58 AM • 4 Comments •
Large scale analysis of mRNA localization in the developing fly embryo.
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Posted on November 6, 2007 11:15 AM • 4 Comments •
Some thoughts on a great talk by Gaudenz Danuser on actin, focal adhesions and G-proteins and cell migration.
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Posted on October 29, 2007 1:26 PM • 1 Comments •
... new research shows that cells have chirality.
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Posted on October 18, 2007 11:45 AM • 7 Comments •
These large complexes limit what goes in and out of the nucleus and are made up of a lot of strange parts. We now find out that NPCs contain a small protein normally found in the Dynein motor.
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Posted on September 17, 2007 10:52 AM • 0 Comments •
One of the most watched cell biology videos of all time. A neutrophil uses chemotaxis to chase a bacterium around a field of red blood cells. Notice how the neutrophil can suddenly change direction. This clip was shot over 50...
Posted on September 15, 2007 8:54 AM • 2 Comments •
From a recent PLoS Genetics paper.
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Posted on September 12, 2007 7:56 PM • 7 Comments •
A ubiquitin like molecule helps fuse vesicles together.
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Posted on September 5, 2007 4:40 PM • 4 Comments •
A nice article in Nature on image-based data
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Posted on August 2, 2007 10:00 AM • 5 Comments •
Guess what's I've captured in this image.
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Posted on August 1, 2007 10:00 AM • 0 Comments •
... don't count on it!
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Posted on July 31, 2007 10:00 AM • 1 Comments •
A connective tissue cell, stained for umodified and detyrosinated microtubules.
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Posted on July 30, 2007 10:00 AM • 6 Comments •
OK here's a post geared mostly to cell biologists. My big pet peeve about the biomedical scientific literature is ... colored fluorescent images.
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Posted on July 29, 2007 10:00 AM • 8 Comments •
In their latest paper, the Moore lab proposes that certain mRNAs are transported up dendrites, translated at the synapse, and then destroyed by NMD. Very cool.
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Posted on July 25, 2007 5:40 PM • 4 Comments •
Some micrographs from a recent experiment that I performed. What do you think?
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Posted on July 16, 2007 11:49 AM • 7 Comments •
Since I first posted on science publishing and the web2.0, various links have popped up and I just wanted to alert you of them.
Posted on July 5, 2007 9:59 AM • 6 Comments •
After the last miRNA post, I was alerted to this paper that appeared in the June 15th edition of Nature: Thimmaiah P. Chendrimada, Kenneth J. Finn, Xinjun Ji, David Baillat, Richard I. Gregory, Stephen A. Liebhaber, Amy E. Pasquinelli &...
Posted on July 3, 2007 11:46 PM • 5 Comments •
Two interesting papers on how miRNAs and argonaute proteins inhibit and potentiate translation.
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Posted on June 25, 2007 8:47 PM • 4 Comments •
I was watching Science Saturday, over at bloggingheads.tv, where Horgan & Johnson were talking about the origin of life and RNA (among other things). Also mentioned was Robert Shapiro's article in Scientific American. Shapiro is an advocate of the cell...
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Posted on June 23, 2007 6:50 PM • 2 Comments •
Last night we met up with Marius Wernig. After drinks, talk turned to stem cells.
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Posted on June 9, 2007 11:50 AM • 1 Comments •
Here's another video for you where Dr Jaenisch discusses this week's incredible findings.
Posted on June 8, 2007 8:46 AM • 3 Comments •
Using four factors, you can transform any somatic cell into a stem cell.
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Posted on June 6, 2007 5:06 PM • 11 Comments •
This month's best in genetics blogging.
Posted on June 3, 2007 12:31 PM • 2 Comments •
Soon it will be clear that this paper from last summer will be the basis of a future Nobel Prize.
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Posted on May 31, 2007 6:59 PM • 21 Comments •
Hear a seminar from one of the pioneers of GFP technology and a leader in the study of cellular organelles.
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Posted on May 25, 2007 8:29 AM • 6 Comments •
This is a cleaned up version of a comment I left on Larry Moran's blog....
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Posted on May 24, 2007 7:44 PM • 4 Comments •
A new hint in the latest issue of
Cell.
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Posted on May 22, 2007 12:14 PM • 10 Comments •
A few days ago I wrote about Ron Breaker and Riboswitches, and today I was alerted to this really neat advanced online publication by the Breaker group on how a riboswitch in Neurospera regulates alternative splicing. Wow. So what...
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Posted on May 21, 2007 9:06 PM • 0 Comments •
So is the theory of semi-conservative replication of centrioles dead?
Posted on May 21, 2007 5:22 PM • 2 Comments •
How are these inserted into membranes? Another fundamental biological activity that up until recently had been a mystery.
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Posted on May 16, 2007 8:33 AM • 0 Comments •
Auxin is a major plant signaling molecule. Ning Zheng's lab shows how it works with IP6 to degrade molecules. In the process we learn a new concept: molecular glue.
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Posted on May 9, 2007 8:40 AM • 4 Comments •
Let's put it this way, if animals, plants and fungi are three siblings, Plasmodium would be their 6th cousin who lives in a trailer-park on the other side of the river. It's a distant relative, but deep down they're all related in an uncanny way.
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Posted on May 4, 2007 8:49 AM • 1 Comments •
Can you identify the mystery organism that causes Joolya's tissue culture cells to bleb?
Posted on May 2, 2007 6:02 PM • 0 Comments •
A bacterium with a nucleiod membrane.
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Posted on May 2, 2007 5:41 PM • 5 Comments •
I had never seen
Eric Olson's seminar before, and it was awesome. Lately the Olson's lab has been looking at HDACs, i.e. histone deacetylases. Knockouts of these proteins are really fascinating.
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Posted on May 1, 2007 7:41 PM • 1 Comments •
T. rex proteins sequenced. Wow.
Posted on April 13, 2007 7:52 AM • 3 Comments •
How come no one told me about this site? STRING is a database of known and predicted protein-protein interactions. The interactions include direct (physical) and indirect (functional) associations; they are derived from four sources: -Genomic Context -High-throughput Experiments -(Conserved) Coexpression...
Posted on April 9, 2007 9:36 AM • 5 Comments •
What happens when you inject fluorescent DNA into cells? Psychedelic micrographs.
Posted on April 3, 2007 6:23 PM • 9 Comments •
How the expression of a single protein can profoundly alter the types of proteins synthesized during mitosis.
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Posted on April 2, 2007 12:04 PM • 3 Comments •
The latest in Genetics Blogging. Come take a look.
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Posted on April 2, 2007 8:35 AM • 2 Comments •
Mitochondria. How do they shuttle proteins and what are they good for. (It's not just oxphos.)
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Posted on March 29, 2007 8:45 AM • 0 Comments •
Some weird feedback loops within mRNA biosynthesis.
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Posted on March 21, 2007 9:30 AM • 4 Comments •
The question I asked, and the followup question I should have asked.
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Posted on March 15, 2007 7:24 PM • 8 Comments •
A new piRNA paper, a new inhibitor of translation and a little something on actin-membrane attachment.
Posted on March 8, 2007 11:53 AM • 6 Comments •
There's a new paper in Dev Cell with a nice reconstruction of a fission yeast cell (S. pombe) with all its microtubules. From the abstract: Here, we describe a large-scale, electron tomography investigation of S. pombe, including a 3D reconstruction...
Posted on March 8, 2007 9:15 AM • 0 Comments •
Some background (and movies) on how actin polymers generate locomotion in cells.
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Posted on March 6, 2007 4:35 PM • 5 Comments •
Notes from a dinner with Kevin Struhl, Danesh Moazed, Steve Buratowski and James Manley.
Posted on February 27, 2007 11:11 AM • 3 Comments •
I guess prokaryotes are looking more and more like eukaryotes. It turns out that their DNA is moved around by cytoskeletal filaments. The most recent (and one of the most dramatic) examples can be seen in a recent article in...
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Posted on February 23, 2007 11:22 AM • 2 Comments •
Last Thursday, Stephan and I "imaged" some macrophages being infected with a vicious strain of vibrio, here's a cool image of one of the poor suckers:
Posted on February 10, 2007 10:00 AM • 2 Comments •
MDR: Multi Drug Resistance Protein. It's an ABC (ATPase Box Cassette) Transporter. In other words, this gene encodes an energy utilizing pump that sits on the plasma membrane and actively transports (mostly hydrophobic?) compounds out of the cell. As I...
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Posted on February 8, 2007 5:02 PM • 4 Comments •
In 1997, 38% of essential genes in
E. coli were unannotated and thus have names that begin with "y". That is, we were clusless as to what their role was. So what is the current figure?
Posted on January 14, 2007 2:45 PM • 3 Comments •
Well the latest paper from the Reed lab (squeeking into Cell on its last issue of 2006) demonstrates that the cap is indeed promoting nuclear export of mRNA in vertebrate cells. (For more on mRNA export, click here.) This idea...
Posted on January 10, 2007 8:31 AM • 2 Comments •
From the latest issue of Science.
Posted on January 6, 2007 7:39 AM • 1 Comments •
In this day, some biologist have to move beyond the simplistic view that the cell is a bag of M&Ms. What do I mean by that? It's the idea that enzymes and organelles are free floating entities within the cell....
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Posted on January 3, 2007 9:19 AM • 4 Comments •
2006 was (again) year of the RNA. Two nobels. The RNA world expanded with the discovery of Piwi RNA. RNAi as a transmittable trait? (Lamarck is vindicated!) We also found out that much of the conserved parts of our genome...
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Posted on December 27, 2006 9:13 AM • 5 Comments •
Check this out: First-in-Human Experience of an Antidote-Controlled Anticoagulant Using RNA Aptamer Technology From the paper:...
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Posted on December 24, 2006 8:12 AM • 5 Comments •
Earlier this week you probably read the whole saga of how researchers tracked down some individuals who could not sense pain. They then identified the gene responsible as SCN9A, a voltage-gated sodium channel and that was published in Nature. But...
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Posted on December 23, 2006 11:29 AM • 2 Comments •
Apparently weak and strong signal sequences are differentially targeted to the ER acording to a
new paper in Cell.
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Posted on December 12, 2006 8:55 AM • 4 Comments •
Yesterday Melissa Moore gave a talk at the School of Public Health here at Harvard Med School. She had lots of data - on nonsense mediated decay (how cells degrade mRNA transcripts with premature stop codons that arise through various...
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Posted on December 8, 2006 8:13 PM • 4 Comments •
Wow, this is how the machine works!
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Posted on December 6, 2006 10:20 AM • 7 Comments •
FG repeats found within the nuclear pore complex, form a gel like matrix. It's all nicely explained in a manuscript that recently appeared in Science.
Posted on December 4, 2006 9:01 AM • 3 Comments •
Earlier today I gave our weekly journal club. As usual there is some large scheme/model/godzilla image associated with the intro/summary. Here's mine ... mRNA nuclear export in yeast: Highlighted are 3 major systems. Many proteins are listed, many more are...
Posted on December 1, 2006 6:58 PM • 2 Comments • 0 TrackBacks
Rich Jorgensen on the RNAi Nobel.
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Posted on November 30, 2006 9:23 AM • 2 Comments • 0 TrackBacks
I finally did the experiment ... and more. Come see the results.
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Posted on November 29, 2006 5:20 PM • 18 Comments • 0 TrackBacks
When I was a grad student, eukaryotes had all the neatest toys ... actin, microtubules, kinesins, dynein, myosin, dynamin, SNAREs ... OK that's not totally true - bacteria had their version of tubulin (the constituent of microtubules), and it's...
Posted on November 29, 2006 10:18 AM • 7 Comments • 0 TrackBacks
I've been doing some digging with respect to the survey of intronless genes that I wrote about yesterday ...
Posted on November 20, 2006 8:22 AM • 5 Comments • 0 TrackBacks
Ask most biologists and they'll tell you that in "higher eukaryotes" all genes have introns. But that's not quite true. Here are some stats from the SEGE (Single Exonic Genes in Eukaryotes) website:
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Posted on November 19, 2006 4:15 PM • 7 Comments • 0 TrackBacks
From the latest JCB: mRNAs that encode proteins responsible for cell cycle regulation, use their own export machinery.
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Posted on November 17, 2006 9:20 AM • 1 Comments • 0 TrackBacks
So the latest piece of the puzzle came in ... I just saw a paper in the latest Nature Cell Biology on how a version of phospholipaseD acts to promote membrane fusion of the outer mitochondrial membrane.
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Posted on November 16, 2006 4:53 PM • 0 Comments • 0 TrackBacks
This is for cell motility aficionados. How do cells crawl? Well most in the field would say that actin polymerization generated by the Arp2/3 complex at the leading edge acts to generate an actin meshwork (see pic). The addition...
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Posted on November 14, 2006 6:36 PM • 3 Comments • 0 TrackBacks
A paper on 1) protein degradation in the nucleus, 2) how membrane bound proteins cross the NPC, and 3) crazy experiments you can perform in yeast.
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Posted on November 6, 2006 3:33 PM • 0 Comments • 0 TrackBacks
Jodi Nunnari's group
has a paper in Cell about how Mgm1, a dynamin like protein found in the inner mitochondrial matrix, is required for inner-membrane
fusion in mitos.
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Posted on October 31, 2006 2:18 PM • 5 Comments • 0 TrackBacks
At that same meeting over the past weekend, I heard Tim Mitchison give an interesting talk about mitosis and pharmacogenetics. For any of you who don't know, Tim's lab has been at the fore front of analyzing how the mitotic...
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Posted on October 26, 2006 1:02 PM • 4 Comments • 0 TrackBacks
Does this type of expression profile look familiar? From my limited experience from these types of pan-tissue blots, it would seem like every damn protein is expressed in testes. Why?...
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Posted on October 25, 2006 10:10 AM • 11 Comments • 0 TrackBacks
When manipulating the constituents of a living organism we can revert to several methods. Specificity and temporal resolution are both critical. How to get the best of both worlds?
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Posted on October 23, 2006 8:49 AM • 2 Comments • 0 TrackBacks
One of the problems in modern day biomedical research is turning on/off protein expression. Now there is a new method that combines protein degradation and pharmacology.
Posted on October 13, 2006 3:44 PM • 4 Comments • 0 TrackBacks
I just read at ScienceSampler that interfering with actin polymerization enhances ethanol tolerance.
If only I knew. The only question left is that will it cure your hangover?
Posted on October 10, 2006 11:32 AM • 0 Comments • 0 TrackBacks
OK a breif history of RNA interference. 1990 Rich Jorgensen at the University of Arizona wanted to make petunias a deeper purple. His group tried expressing extra copies of the same gene and ... he got white flowers. The very...
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Posted on October 2, 2006 7:50 PM • 4 Comments • 0 TrackBacks
About a month ago I wrote an entry on centrosomal RNA. Turns out that the work was not "out of Bob Palazzo's lab" as I asserted but from Mark Alliegro's Lab. His lab has been working on this project for...
Posted on October 2, 2006 4:50 PM • 0 Comments • 0 TrackBacks
We all thought that it was a bit early, but VERY deserved. Also can I add this: The Daily Transcript 1: Thomson Scientific 0. For anyone not in the basic biomedical sciences, the two biggest revolutions in the past 10...
Posted on October 2, 2006 10:11 AM • 10 Comments • 0 TrackBacks
Here is an illustration from a recent PLoS Biology paper: Two complexes: 1- miRNA. Imperfect base pairing between the small RNA and the target. This complex sorts the RNA to p-bodies (processing bodies) where other proteins join in. The mRNA...
Posted on September 28, 2006 3:22 PM • 5 Comments • 0 TrackBacks
Newest from PLoS Biology: Raj A, Peskin CS, Tranchina D, Vargas DY, Tyagi S Stochastic mRNA Synthesis in Mammalian Cells. PLoS Biol (2006) 4(10): e309 The authors genomically incorporated a gene with 32 tandem copies of a 43-base-pair probe-binding sequence...
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Posted on September 27, 2006 8:20 AM • 0 Comments • 0 TrackBacks
There is a nice post by Coffee Mug at Gene Expression on non-coding RNAs (ncRNAs). This post was provoked by a paper in Annual Review of Neuroscience. In light of my post on the recent Eric Lander and David Spector's...
Posted on September 20, 2006 5:29 PM • 9 Comments • 0 TrackBacks
Biology is filled with feedback loops and other natural buffers to promote homeostasis. In the latest Nature, there is a ... cute ... paper about how the RNA export factor Tap (aka NXF1) mediates the nuclear export of an alternatively...
Posted on September 19, 2006 8:54 AM • 1 Comments • 0 TrackBacks
Looks like this season's lecture series has started. Yesterday evening I saw a talk by Eric Lander, head of the Broad Institute. Now normally I do not blog about my results and I do not blog about what I hear...
Posted on September 15, 2006 8:30 AM • 9 Comments • 0 TrackBacks
With a simple 3 point mutation you can direct a protein that is destined for the ER into mitochondria.
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Posted on September 13, 2006 8:45 AM • 1 Comments • 0 TrackBacks
I discovered this wonderful website:
Peoples Archives. In it you'll find interviews with some of the greatest thinkers of the 20th century. I just finished listening to Sydney Brenner and Francis Crick and am now listening to Renato Dulbecco.
Posted on September 5, 2006 8:29 AM • 1 Comments • 0 TrackBacks
Just a quick lab advertisement, my bay mate Yoko and my boss Tom have a review article in Cell about how morphological differences between various regions of the endoplasmic reticulum (ER) are representative of functional differences. You can divide the...
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Posted on September 2, 2006 8:27 AM • 0 Comments • 0 TrackBacks
Inositol-6-phosphate (aka Inositol hexaphosphate, phytic acid, phytate) is a strange compound. Now it turns out that IP6 is a co-factor required for mRNA nuclear export.
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Posted on September 1, 2006 8:30 AM • 3 Comments • 0 TrackBacks
I've often brainstormed with one structural biologist in the lab (he does both crystallography and NMR) on how to solve all of x-ray crystallography's problems by forcing proteins to rearrange themselves in regular arrays. But we haven't come up with anything good strategy yet. BK points to a new theoretical technique that may help.
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Posted on August 29, 2006 8:44 AM • 11 Comments • 0 TrackBacks
(This is an intro to a n upcoming entry.) When I was an undergrad, working in a lab at McGill, my then boss Morag Park would joke that Phosphoinositides were at the center of the universe. What did she mean...
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Posted on August 28, 2006 11:46 AM • 2 Comments • 0 TrackBacks
This is the newest from the Blobel lab. Note to all "they've discovered everything" types: this finding shows how much we know about how cells operate. Background: As I've described before the nucleus and the cytoplasm are two cellular compartments...
Posted on August 27, 2006 1:10 PM • 0 Comments • 0 TrackBacks
Microtubules are long hollow polymers. They are also polar. Their minus ends are inert and are found towards the cell center while their plus ends grow and shrink and are found towards the cell periphery.
Question:
Why are microtubules hollow?
Now a few recent papers have surfaced that report inner-microtubule densities.
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Posted on August 24, 2006 8:48 PM • 3 Comments • 0 TrackBacks
The Cytoskeleton. Now that's what you call a misnomer. It is one of the most fascinating, yet misunderstood, macromolecular assemblies of the cell. Yes, the cytoskeleton can act as a scafold onto which the rest of the cell is drapped...
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Posted on August 22, 2006 5:40 PM • 5 Comments • 0 TrackBacks
Not so long ago I wrote about piRNA. After reading a bit more, there are some points I'd like to make: - It would seem that piRNA (read this for background) are required for proper spermiogenesis. - The argonaute family...
Posted on August 19, 2006 8:55 AM • 0 Comments • 0 TrackBacks