Martin JakobUniversität Bern | UniBe · Institute of Cell Biology
Martin Jakob
MS in Molecular Life Sciences
About
24
Publications
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110
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Citations since 2017
Introduction
Martin Jakob currently works at the Institute of Cell Biology, at the University of Bern. Martin does research in Molecular Cell Biology. Their most recent publication is 'Molecular model of the mitochondrial genome segregation machinery in Trypanosoma brucei'.
Education
August 2009 - August 2012
Publications
Publications (24)
The unicellular parasite Trypanosoma brucei harbors one mitochondrial organelle with a singular genome called the kinetoplast DNA (kDNA). The kDNA consists of a network of concatenated minicircles and a few maxicircles that form the kDNA disc. More than 30 proteins involved in kDNA replication have been described. However, several mechanistic quest...
Significance
Mitochondrial genome replication and segregation are essential processes in most eukaryotic cells. While replication has been studied in some detail, much less is known about the molecular machinery required to distribute the replicated genomes. Using superresolution microscopy in combination with molecular biology and biochemistry, we...
The unicellular parasite Trypanosoma brucei harbors one individual mitochondrial organelle with a singular genome the kinetoplast DNA or kDNA. The kDNA largely consists of concatenated minicircles and a few maxicircles that are also interlocked into the kDNA disc. More than 30 proteins involved in kDNA replication have been described, however sever...
In almost all eukaryotes mitochondria maintain their own genome. Despite the discovery more than 50 years ago still very little is known about how the genome is properly segregated during cell division. The protozoan parasite Trypanosoma brucei contains a single mitochondrion with a singular genome the kinetoplast DNA (kDNA). Electron microscopy st...
RNA recognition motif (RRM) containing proteins are important regulators of gene expression in trypanosomes. Here we expand our current knowledge on the exclusively nuclear localized RRM domain containing protein RBP33 of Trypanosoma brucei. Overexpression of RBP33 leads to a quick growth arrest in G2/M in bloodstream form cells likely due to an ov...
Mitochondrial organelles need to be replicated during cell division. Many aspects of this process have been studied in great detail, however the actual size increase and the position of organelle growth are less well understood. We use the protozoan parasite Trypanosoma brucei that contains a single mitochondrion to study organelle biogenesis by fl...
We recently described a new component (TAC102) of the mitochondrial genome segregation machinery (mtGSM) in the protozoan parasite Trypanosoma brucei. T. brucei belongs to a group of organisms that contain a single mitochondrial organelle with a single mitochondrial genome (mt-genome) per cell. The mt-genome consists of 5000 minicircles (1 kb) and...
[This corrects the article DOI: 10.1371/journal.ppat.1005586.].
Republished, corrected article.
(PDF)
Originally published, uncorrected article.
(PDF)
Author
Proper segregation of the mitochondrial genome during cell division is a prerequisite of healthy eukaryotic cells. However, the mechanism underlying the segregation process is only poorly understood. We use the single celled parasite Trypanosoma brucei, which, unlike most model organisms, harbors a single large mitochondrion with a single m...
Conservation and posttranslational modification of TAC102.
A–a stick figure displaying conserved regions (violet) of the TAC102 protein sequence as well as phosphorylation sites at positions 609 and 614. The non-conserved regions are depicted in pink. B–a phylogenetic tree showing conservation of TAC102 among Kinetoplastea. The tree was reconstruct...
Flagella isolated from PCF cells retain TAC102.
Flagella were extracted from PCF trypanosomes with 0.5% TritonX-100, as described in Materials and Methods, and treated with DNAse I or left untreated. A–immunofluorescence images showing: an untreated flagellum (upper panel) that retains the kDNA (stained with DAPI, cyan) and TAC102 (magenta); a DNAs...
Ectopic expression of the myc:full, myc:ΔN and myc:ΔC versions of TAC102 in PCF cells followed for five days upon induction.
DNA is stained with DAPI (cyan) and myc-tagged proteins (visualized by anti-myc antibody) are shown in magenta. Expression of the myc:full protein (upper set of panels) does not affect the kDNA and the protein localizes to th...
RNAi against TAC102 in BSF cells induced for 18 hours.
At this early time point, some cells lose the TAC102 signal as well as the kDNA, but it happens preferably at the more posterior basal body (examples in the middle panel and the lower panel, compare to non-induced cells in the upper panel). YL1/2 is used as a basal body marker (green), TAC102 i...
Quantification of k-n-numbers and ancillary kinetoplasts in selected cell lines.
A–a column chart showing percentages of cells with different k-n-numbers in the following PCF cell lines: myc:full, overexpression for five days (red); myc:ΔN (overexpression for five days (green); RNAi against the 3’-UTR of TAC102, non-induced cells (blue); RNAi again...
Amphipathic helices at the C-terminus of TAC102.
The schematic alpha-helices show the last 18 aa (A) or 36 aa (B) of the C-terminal sequence of TAC102. The schemes were constructed by the online tool available at http://rzlab.ucr.edu/scripts/wheel/wheel.cgi. Hydrophilic residues are shown as circles, hydrophobic residues–as diamonds, potentially ne...
Ectopic expression of GFP chimeras C-terminally fused with C-terminal parts of TAC102 in PCF cells.
Expression was induced overnight. Immunofluorescence images show the localization of the GFP chimeras (visualized by anti-GFP antibody, green). ATOM is a mitochondrial marker protein, visualized by anti-ATOM antibody (red). DNA is stained with DAPI (...
TAC102 RNAi in PCF cells and antibodies against TAC102.
A-C: RNAi against the ORF of TAC102 in PCF cells. A–a growth curve showing the onset of a growth defect after day 4 of RNAi induction. Inset: a northern blot confirming downregulation of TAC102 mRNA after two days of RNAi induction. 18S rRNA is used as a loading control. B–epifluorescence imag...
PCF cells expressing GFP-301aa after 1 hour of induction.
The GFP chimera is visualized by anti-GFP antibody (green). The mitochondrial heat-shock protein 70 (mtHSP70) is used as a mitochondrial marker (red). DNA is stained with DAPI (cyan). At this early time point of induction, few cells express GFP-301aa, which makes its detection by western blo...
Questions
Questions (10)
Hello Community,
I'm not very familiar with these kind of tasks and my web development skills could also be better. If anyone is familiar with how to get the source code of an external web site using jquery, javascript, ajax or whatever it would be very cool! :-)
The situation is as follows: I have a list of URLs that were built using a CMS. To the CMS, however, I have no access whatsoever. The previous task was to move all the images by Drag&Drop from an old destination to a new one. Since I'm sure that a lot of images were skipped, my idea was to search the source codes for each occurance of "<img" until a ">" appears. Then within each of these substrings I would search and test whether the new path is missing, and if so, I would list the image name and the page it appears on. That would facilitate the task of checking for forgotten images a big time. My idea was to obtain the source code of these URLs as a sting-variable and fill it into a text area within an html form. Then, once one site was completed, it would do the same for the next page, and so on. The problem with this method (php) is that it requires that the site is refreshed after loading each source code. Maybe some javascript method would be faster?!
I would also appreciate other, maybe less awkward ideas. Also if anyone could hint me to some code snippets I would be very happy.
thanks in advance,
Martin
Hello ImageJ people,
I have a macro file with which I want to invert parts of the image. This works fine so far. The problem however kicks in, when it's an "8-bit color" image. Inversion does not work with them, which makes sense, since there is a limitation of max. 256 distinct color tones. My roundabout would be to convert the image type to "RGB color" first, and only then invert. Now, how do I distinguish both types: "8-bit" and "8-bit color" in a macro? With the command bitDepth(); I can only tell the bit depth but not whether its mode is grayscale or color. Also, my worst-case idea of splitting the colors by run("Split Channels"), then check the contents of the R,G, and B image and re-merge them into an RGB color image if they differ does not work. As far as I understood now, "8-bit color" images use a special Lookup table in which the values 0-255 are assigned an RGB display color. My next idea would be to go through the LUT with getLut(reds, greens, blues) - but this seems to be a very brute force solution. Any easier suggestions?
Thanks Martin
