| 1. |
- Björkblom, Benny, et al.
(författare)
-
Constitutively Active Cytoplasmic c-Jun N-Terminal Kinase 1 Is a Dominant Regulator of Dendritic Architecture: Role of Microtubule-Associated Protein 2 as an Effector
- 2005
-
Ingår i: Journal of Neuroscience. - : Society for Neuroscience. - 0270-6474 .- 1529-2401. ; 25:27, s. 6350-6361
-
Tidskriftsartikel (refereegranskat)abstract
- Normal functioning of the nervous system requires precise regulation of dendritic shape and synaptic connectivity. Here, we report a severe impairment of dendritic structures in the cerebellum and motor cortex of c-Jun N-terminal kinase 1 (JNK1)-deficient mice. Using an unbiased screen for candidate mediators, we identify the dendrite-specific high-molecular-weight microtubule-associated protein 2 (MAP2) as a JNK substrate in the brain. We subsequently show that MAP2 is phosphorylated by JNK in intact cells and that MAP2 proline-rich domain phosphorylation is decreased in JNK1-/- brain. We developed compartment-targeted JNK inhibitors to define whether a functional relationship exists between the physiologically active, cytosolic pool of JNK and dendritic architecture. Using these, we demonstrate that cytosolic, but not nuclear, JNK determines dendritic length and arbor complexity in cultured neurons. Moreover, we confirm that MAP2-dependent process elongation is enhanced after activation of JNK. Using JNK1-/- neurons, we reveal a dominant role for JNK1 over ERK in regulating dendritic arborization, whereas ERK only regulates dendrite shape under conditions in which JNK activity is low (JNK1-/- neurons). These results reveal a novel antagonism between JNK and ERK, potentially providing a mechanism for fine-tuning the dendritic arbor. Together, these data suggest that JNK phosphorylation of MAP2 plays an important role in defining dendritic architecture in the brain.
|
|
| 2. |
- Moulder, Robert, et al.
(författare)
-
A comparative evaluation of software for the analysis of liquid chromatography-tandem mass spectrometry data from isotope coded affinity tag experiments
- 2005
-
Ingår i: Proteomics. - : Wiley-VCH Verlagsgesellschaft. - 1615-9853 .- 1615-9861. ; 5:11, s. 2748-2760
-
Tidskriftsartikel (refereegranskat)abstract
- The options available for processing quantitative data from isotope coded affinity tag (ICAT) experiments have mostly been confined to software specific to the instrument of acquisition. However, recent developments with data format conversion have subsequently increased such processing opportunities. In the present study, data sets from ICAT experiments, analysed with liquid chromatography/tandem mass spectrometry (MS/MS), using an Applied Biosystems QSTAR Pulsar quadrupole-TOF mass spectrometer, were processed in triplicate using separate mass spectrometry software packages. The programs Pro ICAT, Spectrum Mill and SEQUEST with XPRESS were employed. Attention was paid towards the extent of common identification and agreement of quantitative results, with additional interest in the flexibility and productivity of these programs. The comparisons were made with data from the analysis of a specifically prepared test mixture, nine proteins at a range of relative concentration ratios from 0.1 to 10 (light to heavy labelled forms), as a known control, and data selected from an ICAT study involving the measurement of cytokine induced protein expression in human lymphoblasts, as an applied example. Dissimilarities were detected in peptide identification that reflected how the associated scoring parameters favoured information from the MS/MS data sets. Accordingly, there were differences in the numbers of peptides and protein identifications, although from these it was apparent that both confirmatory and complementary information was present. In the quantitative results from the three programs, no statistically significant differences were observed.
|
|
| 3. |
- Moulder, Robert, et al.
(författare)
-
Quantitative proteomics analysis of the nuclear fraction of human CD4+ cells in the early phases of IL-4-induced Th2 differentiation
- 2010
-
Ingår i: Molecular & Cellular Proteomics. - : American Society for Biochemistry and Molecular Biology. - 1535-9476 .- 1535-9484. ; 9:9, s. 1937-1953
-
Tidskriftsartikel (refereegranskat)abstract
- We used stable isotope labeling with 4-plex iTRAQ (isobaric tags for relative and absolute quantification) reagents and LC-MS/MS to investigate proteomic changes in the nucleus of activated human CD4(+) cells during the early stages of Th2 cell differentiation. The effects of IL-4 stimulation upon activated naïve CD4(+) cells were measured in the nuclear fractions from 6 and 24 h in three biological replicates, each using pooled cord blood samples derived from seven or more individuals. In these analyses, in the order of 800 proteins were detected with two or more peptides and quantified in three biological replicates. In addition to consistent differences observed with the nuclear localization/expression of established human Th2 and Th1 markers, there were changes that suggested the involvement of several proteins either only recently reported or otherwise not known in this context. These included SATB1 and among the novel changes detected and validated an IL-4-induced increase in the level of YB1. This unique data set from human cord blood CD4(+) T cells details an extensive list of protein determinations that compares with and complements previous data determined from the Jurkat cell nucleus.
|
|
