| 1. |
- Andersson, Leif, et al.
(författare)
-
ZBED6 : the birth of a new transcription factor in the common ancestor of placental mammals
- 2010
-
Ingår i: Transcription. - : Informa UK Limited. - 2154-1272 .- 2154-1264. ; 1:3, s. 144-148
-
Tidskriftsartikel (refereegranskat)abstract
- A DNA transposon integrated into -the genome of a primitive mammal some 200 million years ago and, millions of years later, it evolved an essential function in the common ancestor of all placental mammals. This protein, now named ZBED6, was recently discovered because a mutation disrupting one of its binding sites, in an intron of the IGF2 gene, makes pigs grow more muscle. These findings have revealed a new mechanism for regulating muscle growth as well as a novel transcription factor that appears to be of major importance for transcriptional regulation in placental mammals.
|
|
| 2. |
- Hjälm, Göran, et al.
(författare)
-
Cloning and sequencing of human gp330, a Ca2+ -binding receptor with potential intracellular signaling properties
- 1996
-
Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 239:1, s. 132-137
-
Tidskriftsartikel (refereegranskat)abstract
- We present here the complete primary structure of human gp330, the human variant of the principal kidney autoantigen causing Heymann membranous glomerulonephritis in rats. The deduced 4655 amino acid residues give a calculated molecular mass of 519636 Da for the mature protein and consists of a probable 25-amino-acid N-terminal signal peptide sequence, an extracellular region of 4398 amino acids, a single transmembrane-spanning domain of 23 amino acids, and an intracellular C-terminal region of 209 amino acid residues. Three types of cysteine-rich repeats characteristic of the low density lipoprotein receptor (LDLR) superfamily are present in human gp330. In the extracellular region, there are a total of 36 LDLR ligand-binding repeats, comprising four distinct domains, 16 growth factor repeats separated by eight YWTD spacer regions, and one epidermal growth factor-like repeat. No consensus cleavage sequence for the processing endoprotease furin is detected in human gp330. The intracellular tail contains not only two copies of the F(X)NPXY coated-pit mediated internalization signal characteristic of LDLR superfamily members, but also intriguing and potentially functional motifs including several Src-homology 3 recognition motifs, one Src-homology 2 recognition motif for the p85 regulatory subunit of phosphatidylinositol 3-kinase, and additional sites for protein kinase C, casein kinase II and cAMP-/cGMP-dependent protein kinase. There is approximately 77% amino acid identity between human and rat gp330 with minor differences between the extracellular and intracellular regions. Recently gp330 has been implicated in Ca2+ regulation in the parathyroid, the placenta, and the renal tubule, but its overall physiological and pathological role still remains uncertain.
|
|
| 3. |
- Lundgren, Stefan, et al.
(författare)
-
Tissue distribution of human gp330/megalin, a putative Ca2+-sensing protein
- 1997
-
Ingår i: Journal of Histochemistry and Cytochemistry. - : SAGE Publications. - 0022-1554 .- 1551-5044. ; 45:3, s. 383-392
-
Tidskriftsartikel (refereegranskat)abstract
- We used riboprobes and monoclonal antibodies to characterize tissue distribution of the human 550-kD homologue to gp330/megalin, primarily identified in the rat kidney. Human gp330/megalin mRNA and protein are readily identified in human parathyroid cells, placental cytotrophoblasts, kidney proximal tubule cells, and epididymal epithelial cells. The immunoreactivity is found on the surface of the cells and is heterogeneously downregulated in parathyroid hyperplasia and adenomas. Cells of the proximal kidney tubule and epididymis express the protein on their luminal aspect. Moreover, the protein is expressed in Type II pneumocytes, mammary epithelial and thyroid follicular cells, and the ciliary body of the eye. Sequence analysis of cDNA fragments, obtained by RT-PCR, revealed identical nucleotide sequences in parathyroid, kidney, placenta, epididymis, and lung. Immunohistochemistry for parathyroid hormone-related protein (PTHrP) revealed partial co-expression with human gp330/megalin in parathyroid, placenta, and mammary gland. The findings substantiate human gp330/megalin expression in a variety of human tissues expected to possess calcium-sensing functions. It may constitute a protein of utmost importance to adult and fetal calcium homeostasis, although other important functions may also be coupled to this exceptionally large protein with highly restricted tissue distribution.
|
|
| 4. |
- Markljung, Ellen, 1978-
(författare)
-
QTL Analysis in the Pig : From the Identification of Quantitative Trait Loci to the Understanding of Molecular Mechanisms
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Domestic pigs have become very different form the wild ancestors they originate from. Selection for muscle growth and meat quality has made the pig a good model for genetic studies of muscle development.The first part of this thesis presents a genome-wide scan for quantitative trait loci (QTL) in a cross between Landrace and Hampshire pigs. Traits such as body composition, fat deposition, body length, meat quality and weight measurements of individual muscles were investigated. In total we identified 15 different QTLs that reached genome-wide significance. The three most significant QTLs were for carcass length on chromosome 17 and two overlapping QTLs on chromosome 1 for body composition and weight of M. biceps femoris, respectively. A strong candidate gene for the body composition QTL is melanocortin 4 receptor (MC4R). We also identified several QTLs for sizes of different muscles, fat deposition and meat quality traits.In a previous study using a cross between the domestic Large White and wild boar, the mutation underlying a major QTL for muscle growth and fat deposition was identified as a single nucleotide substitution (QTN) in intron 3 of the IGF2 gene. The QTN disrupts the binding of a repressor affecting IGF2 mRNA expression. In the second part of this thesis, the identification of the repressor is presented. The repressor, named ZBED6, is a previously unknown mammalian member of the BED-domain protein family. We could show that Zbed6 specifically binds the wild-type but not the mutated sequence surrounding the QTN. Further studies of silenced Zbed6 in the mouse myoblast cell line C2C12 showed that it represses transcription in a luciferase reporter assay and affects Igf2 mRNA transcription and proliferation. ZBED6 shows very high sequence conservation and has a broad tissue distribution of expression suggesting that ZBED6 also has important biological function outside the muscle cell.
|
|
| 5. |
- Markljung, Ellen, et al.
(författare)
-
ZBED6, a novel transcription factor derived from a domesticated DNA transposon regulates IGF2 expression and muscle growth
- 2009
-
Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 7:12, s. e1000256-
-
Tidskriftsartikel (refereegranskat)abstract
- A single nucleotide substitution in intron 3 of IGF2 in pigs abrogates a binding site for a repressor and leads to a 3-fold up-regulation of IGF2 in skeletal muscle. The mutation has major effects on muscle growth, size of the heart, and fat deposition. Here, we have identified the repressor and find that the protein, named ZBED6, is previously unknown, specific for placental mammals, and derived from an exapted DNA transposon. Silencing of Zbed6 in mouse C2C12 myoblasts affected Igf2 expression, cell proliferation, wound healing, and myotube formation. Chromatin immunoprecipitation (ChIP) sequencing using C2C12 cells identified about 2,500 ZBED6 binding sites in the genome, and the deduced consensus motif gave a perfect match with the established binding site in Igf2. Genes associated with ZBED6 binding sites showed a highly significant enrichment for certain Gene Ontology classifications, including development and transcriptional regulation. The phenotypic effects in mutant pigs and ZBED6-silenced C2C12 myoblasts, the extreme sequence conservation, its nucleolar localization, the broad tissue distribution, and the many target genes with essential biological functions suggest that ZBED6 is an important transcription factor in placental mammals, affecting development, cell proliferation, and growth.
|
|
| 6. |
- Andersson, Lisa, et al.
(författare)
-
Mutations in DMRT3 affect locomotion in horses and spinal circuit function in mice
- 2012
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 488:7413, s. 642-646
-
Tidskriftsartikel (refereegranskat)abstract
- Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement(1). These networks produce left-right alternation of limbs as well as coordinated activation of flexor and extensor muscles(2). Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favourable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is expressed in the dI6 subdivision of spinal cord neurons, takes part in neuronal specification within this subdivision, and is critical for the normal development of a coordinated locomotor network controlling limb movements. Our discovery positions Dmrt3 in a pivotal role for configuring the spinal circuits controlling stride in vertebrates. The DMRT3 mutation has had a major effect on the diversification of the domestic horse, as the altered gait characteristics of a number of breeds apparently require this mutation.
|
|
| 7. |
- Barnes, Brian R, et al.
(författare)
-
5'-AMP-activated protein kinase regulates skeletal muscle glycogen content and ergogenics
- 2005
-
Ingår i: The FASEB Journal. - : Wiley. - 0892-6638 .- 1530-6860. ; 19:7, s. 773-779
-
Tidskriftsartikel (refereegranskat)abstract
- 5'-AMP-activated protein kinase (AMPK) activity is increased during exercise in an intensity- and glycogen-dependent manner. We previously reported that a mutation in the AMPK3 subunit (Prkag3225Q) increases AMPK activity and skeletal muscle glycogen content. Transfection experiments revealed the R225Q mutation is associated with high basal AMPK activity and diminished AMP dependence. Thus, the R225Q mutation can be considered a loss-of-function mutation that abolished allosteric regulation by AMP/ATP, causing increased basal AMPK activity. We used AMPK3 transgenic (Tg-Prkag3225Q) and knockout (Prkag3-/-) mice to determine the relationship between AMPK activity, glycogen content, and ergogenics (ability to perform work) in isolated extensor digitorum longus skeletal muscle after contractions induced by electrical stimulation. Contraction-induced AMPK activity was inversely coupled to glycogen content in wild-type and Tg-Prkag3225Q mice, but not in Prkag3-/- mice, highlighting a partial feedback control of glycogen on contraction-induced AMPK activity in the presence of a functional AMPK3 isoform. Skeletal muscle glycogen content was positively correlated to work performance, regardless of genotype. Thus, chronic activation of AMPK by the Prkag3225Q mutation directly influences skeletal muscle ergogenics by enhancing glycogen content. In conclusion, functional studies of the AMPK3 isoform further support the close connection between glycogen content and exercise performance in skeletal muscle.
|
|
| 8. |
- Barnes, Brian R, et al.
(författare)
-
The 5'-AMP-activated protein kinase gamma3 isoform has a key role in carbohydrate and lipid metabolism in glycolytic skeletal muscle
- 2004
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 279:37, s. 38441-38447
-
Tidskriftsartikel (refereegranskat)abstract
- 5'-AMP-activated protein kinase (AMPK) is a metabolic stress sensor present in all eukaryotes. A dominant missense mutation (R225Q) in pig PRKAG3, encoding the muscle-specific gamma3 isoform, causes a marked increase in glycogen content. To determine the functional role of the AMPK gamma3 isoform, we generated transgenic mice with skeletal muscle-specific expression of wild type or mutant (225Q) mouse gamma3 as well as Prkag3 knockout mice. Glycogen resynthesis after exercise was impaired in AMPK gamma3 knock-out mice and markedly enhanced in transgenic mutant mice. An AMPK activator failed to increase skeletal muscle glucose uptake in AMPK gamma3 knock-out mice, whereas contraction effects were preserved. When placed on a high fat diet, transgenic mutant mice but not knock-out mice were protected against excessive triglyceride accumulation and insulin resistance in skeletal muscle. Transfection experiments reveal the R225Q mutation is associated with higher basal AMPK activity and diminished AMP dependence. Our results validate the muscle-specific AMPK gamma3 isoform as a therapeutic target for prevention and treatment of insulin resistance.
|
|
| 9. |
- Brechmann, Nils Arnold, et al.
(författare)
-
Pilot-scale process for magnetic bead purification of antibodies directly from non-clarified CHO cell culture
- 2019
-
Ingår i: Biotechnology progress (Print). - : AIChE. - 8756-7938 .- 1520-6033.
-
Tidskriftsartikel (refereegranskat)abstract
- High capacity magnetic protein A agarose beads, LOABeads PrtA, were used in the developmentof a new process for affinity purification of monoclonal antibodies (mAbs) from non-clarifiedCHO cell broth using a pilot-scale magnetic separator. The LOABeads had a maximum bindingcapacity of 65 mg/mL and an adsorption capacity of 25–42 mg IgG/mL bead in suspension for anIgG concentration of 1 to 8 g/L. Pilot-scale separation was initially tested in a mAb capture stepfrom 26 L clarified harvest. Small-scale experiments showed that similar mAb adsorptions wereobtained in cell broth containing 40 Å~ 106 cells/mL as in clarified supernatant. Two pilot-scalepurification runs were then performed on non-clarified cell broth from fed-batch runs of 16 L,where a rapid mAb adsorption ≥96.6% was observed after 1 h. This process using 1 L of magnetic beads had an overall mAb yield of 86% and 16 times concentration factor. After this single proteinA capture step, the mAb purity was similar to the one obtained by column chromatography, whilethe host cell protein content was very low, <10 ppm. Our results showed that this magnetic beadmAb purification process, using a dedicated pilot-scale separation device, was a highly efficientsingle step, which directly connected the culture to the downstream process without cell clarification.Purification of mAb directly from non-clarified cell broth without cell separation can providesignificant savings in terms of resources, operation time, and equipment, compared to legacy procedure of cell separation followed by column chromatography step.
|
|
| 10. |
- Eriksson, Jonas
(författare)
-
Genetic and Genomic Studies in Chicken : Assigning Function to Vertebrate Genes
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A major challenge in the post-genomic era is to understand how genome sequence variants (genotype) give rise to the enormous diversity observed in terms of morphology, physiology and behavior (phenotype) among living organisms. Domestic animals—with their tremendous phenotypic variation—are excellent model organisms for determining the relationships between genotype and phenotype. In this thesis, I describe the utilization of the chicken, in combination with modern genetic and genomic approaches, in developing our understanding of the genetic mechanisms underlying phenotypic variation. These studies provide novel information on the genetics behind variation in carotenoid- and melanin-based pigmentation—observed in many organisms—and also cast light on the genetic basis of chicken domestication. In paper I, we report that the yellow skin phenotype—observed in most commercial chickens—is caused by one or several tissue-specific mutations altering the expression of beta-carotene oxygenase 2 (BCO2 or BCDO2) in skin. In addition, we present the first conclusive evidence of a hybrid origin of the domestic chicken, since the allele causing yellow skin most likely originates from the grey jungle fowl (Gallus sonneratii) and not from the previously described sole ancestor, the red jungle fowl (Gallus gallus). In paper II, we detect a number of loci that were likely important during the domestication process of chicken and the later specialization into meat (broiler) and egg (layer) producing lines. One of the major findings was that worldwide, almost all domestic chickens carry a missense mutation in TSHR (thyroid stimulating hormone receptor) in a position that is completely conserved amongst vertebrates. We speculate that this “domestication-mutation” has played an important role in the transformation of the wild red jungle fowl ancestor into the modern domestic chicken. In paper III, we demonstrate that the dilution of red (pheomelanin) pigmentation—observed in the plumage of the Inhibitor of Gold chicken—is caused by a frame-shift mutation in the catechol-O-methyltransferase domain containing 1 (COMTD1) gene. The production and regulation of pheomelanin is poorly understood and this discovery advances our current knowledge of this pathway.
|
|
