Schönau am Königssee, Germany
Schönau am Königssee, Germany

Time filter

Source Type

Mann K.,Max Planck Institute For Biochemie | Wilt F.H.,University of California at Berkeley | Poustka A.J.,Max Planck Institute For Molekulare Genetik
Proteome Science | Year: 2010

Background: The sea urchin embryo has been an important model organism in developmental biology for more than a century. This is due to its relatively simple construction, translucent appearance, and the possibility to follow the fate of individual cells as development to the pluteus larva proceeds. Because the larvae contain tiny calcitic skeletal elements, the spicules, they are also important model organisms for biomineralization research. Similar to other biominerals the spicule contains an organic matrix, which is thought to play an important role in its formation. However, only few spicule matrix proteins were identified previously.Results: Using mass spectrometry-based methods we have identified 231 proteins in the matrix of the S. purpuratus spicule matrix. Approximately two thirds of the identified proteins are either known or predicted to be extracellular proteins or transmembrane proteins with large ectodomains. The ectodomains may have been solubilized by partial proteolysis and subsequently integrated into the growing spicule. The most abundant protein of the spicule matrix is SM50. SM50-related proteins, SM30-related proteins, MSP130 and related proteins, matrix metalloproteases and carbonic anhydrase are among the most abundant components.Conclusions: The spicule matrix is a relatively complex mixture of proteins not only containing matrix-specific proteins with a function in matrix assembly or mineralization, but also: 1) proteins possibly important for the formation of the continuous membrane delineating the mineralization space; 2) proteins for secretory processes delivering proteinaceous or non-proteinaceous precursors; 3) or proteins reflecting signaling events at the cell/matrix interface. Comparison of the proteomes of different skeletal matrices allows prediction of proteins of general importance for mineralization in sea urchins, such as SM50, SM30-E, SM29 or MSP130. The comparisons also help point out putative tissue-specific proteins, such as tooth phosphodontin or specific spicule matrix metalloproteases of the MMP18/19 group. Furthermore, the direct sequence analysis of peptides by MS/MS validates many predicted genes and confirms the existence of the corresponding proteins. © 2010 Mann et al; licensee BioMed Central Ltd.

Gligoris T.G.,University of Oxford | Scheinost J.C.,University of Oxford | Burmann F.,Max Planck Institute For Biochemie | Petela N.,University of Oxford | And 7 more authors.
Science | Year: 2014

Through their association with a kleisin subunit (Scc1), cohesin's Smc1 and Smc3 subunits are thought to form tripartite rings that mediate sister chromatid cohesion. Unlike the structure of Smc1/Smc3 and Smc1/Scc1 interfaces, that of Smc3/Scc1 is not known. Disconnection of this interface is thought to release cohesin from chromosomes in a process regulated by acetylation. We show here that the N-terminal domain of yeast Scc1 contains two α helices, forming a four-helix bundle with the coiled coil emerging from Smc3's adenosine triphosphatase head. Mutations affecting this interaction compromise cohesin's association with chromosomes. The interface is far from Smc3 residues, whose acetylation prevents cohesin's dissociation from chromosomes. Cohesin complexes holding chromatids together in vivo do indeed have the configuration of hetero-trimeric rings, and sister DNAs are entrapped within these. © 2014, American Association for the Advancement of Science. All rights reserved.

Gerisch G.,Max Planck Institute For Biochemie
PMC Biophysics | Year: 2010

This report deals with actin waves that are spontaneously generated on the planar, substrate-attached surface of Dictyostelium cells. These waves have the following characteristics. (1) They are circular structures of varying shape, capable of changing the direction of propagation. (2) The waves propagate by treadmilling with a recovery of actin incorporation after photobleaching of less than 10 seconds. (3) The waves are associated with actin-binding proteins in an ordered 3-dimensional organization: with myosin-IB at the front and close to the membrane, the Arp2/3 complex throughout the wave, and coronin at the cytoplasmic face and back of the wave. Coronin is a marker of disassembling actin structures. (4) The waves separate two areas of the cell cortex that differ in actin structure and phosphoinositide composition of the membrane. The waves arise at the border of membrane areas rich in phosphatidylinositol (3,4,5) trisphosphate (PIP3). The inhibition of PIP3 synthesis reversibly inhibits wave formation. (5) The actin wave and PIP3 patterns resemble 2-dimensional projections of phagocytic cups, suggesting that they are involved in the scanning of surfaces for particles to be taken up. © 2010 Gerisch.

Mann K.,Max Planck Institute For Biochemie | Edsinger E.,University of California at Berkeley | Edsinger E.,Okinawa Institute of Science and Technology
Proteome Science | Year: 2014

Background: Although the importance of proteins of the biomineral organic matrix and their posttranslational modifications for biomineralization is generally recognized, the number of published matrix proteomes is still small. This is mostly due to the lack of comprehensive sequence databases, usually derived from genomic sequencing projects. However, in-depth mass spectrometry-based proteomic analysis, which critically depends on high-quality sequence databases, is a very fast tool to identify candidates for functional biomineral matrix proteins and their posttranslational modifications. Identification of such candidate proteins is facilitated by at least approximate quantitation of the identified proteins, because the most abundant ones may also be the most interesting candidates for further functional analysis.Results: Re-quantification of previously identified Lottia shell matrix proteins using the intensity-based absolute quantification (iBAQ) method as implemented in the MaxQuant identification and quantitation software showed that only 57 of the 382 accepted identifications constituted 98% of the total identified matrix proteome. This group of proteins did not contain obvious intracellular proteins, such as cytoskeletal components or ribosomal proteins, invariably identified as minor components of high-throughput biomineral matrix proteomes. Fourteen of these major proteins were phosphorylated to a variable extent. All together we identified 52 phospho sites in 20 of the 382 accepted proteins with high confidence.Conclusions: We show that iBAQ quantitation may be a useful tool to narrow down the group of functional biomineral matrix protein candidates for further research in cell biology, genetics or materials research. Knowledge of posttranslational modifications in these major proteins could be a valuable addition to previously published proteomes. This is true especially for phosphorylation, because this modification was already shown to modify mineralization processes in some instances. © 2014 Mann and Edsinger; licensee BioMed Central Ltd.

Wagener N.,Max Planck Institute For Biochemie | Wagener N.,Ludwig Maximilians University of Munich | Ackermann M.,Max Planck Institute For Biochemie | Ackermann M.,Ludwig Maximilians University of Munich | And 3 more authors.
Molecular Cell | Year: 2011

The AAA+ family in eukaryotes has many members in various cellular compartments with a role in protein unfolding and degradation. We show that the mitochondrial AAA-ATPase Bcs1 has an unusual function in protein translocation. Bcs1 mediates topogenesis of the Rieske protein, Rip1, a component of respiratory chains in bacteria, mitochondria, and chloroplasts. The oligomeric AAA-ATPase Bcs1 is involved in export of the folded Fe-S domain of Rip1 across the inner membrane and insertion of its transmembrane segment into an assembly intermediate of the cytochrome bc 1 complex, thus revealing an unexpected mechanistical concept of protein translocation across membranes. Furthermore, we describe structural elements of Rip1 required for recognition and export by as well as ATP-dependent lateral release from the AAA-ATPase. In bacteria and chloroplasts Rip1 uses the Tat machinery for topogenesis; however, mitochondria have lost this machinery during evolution and a member of the AAA-ATPase family has taken over its function. © 2011 Elsevier Inc.

Mann K.,Max Planck Institute For Biochemie | Mann M.,Max Planck Institute For Biochemie
Proteome Science | Year: 2011

Background: Hen's egg white has been the subject of intensive chemical, biochemical and food technological research for many decades, because of its importance in human nutrition, its importance as a source of easily accessible model proteins, and its potential use in biotechnological processes. Recently the arsenal of tools used to study the protein components of egg white has been complemented by mass spectrometry-based proteomic technologies. Application of these fast and sensitive methods has already enabled the identification of a large number of new egg white proteins. Recent technological advances may be expected to further expand the egg white protein inventory.Results: Using a dual pressure linear ion trap Orbitrap instrument, the LTQ Orbitrap Velos, in conjunction with data analysis in the MaxQuant software package, we identified 158 proteins in chicken egg white with two or more sequence unique peptides. This group of proteins identified with very high confidence included 79 proteins identified in egg white for the first time. In addition, 44 proteins were identified tentatively.Conclusions: Our results, apart from identifying many new egg white components, indicate that current mass spectrometry technology is sufficiently advanced to permit direct identification of minor components of proteomes dominated by a few major proteins without resorting to indirect techniques, such as chromatographic depletion or peptide library binding, which change the composition of the proteome. © 2011 Mann and Mann; licensee BioMed Central Ltd.

Gomis-Ruth F.X.,Molecular Biology Institute of Barcelona | Botelho T.O.,Molecular Biology Institute of Barcelona | Bode W.,Max Planck Institute For Biochemie
Biochimica et Biophysica Acta - Proteins and Proteomics | Year: 2012

Visualization of three-dimensional structures is essential to the transmission of information to the general reader and the comparison of related structures. Therefore, it would be useful to provide a common framework. Based on the work of Schechter and Berger, and the finding that most peptidases bind their substrates in extended conformation, we suggest a "standard orientation" for the overall description of metallopeptidases (MPs) as done before for peptidases of other classes. This entails a frontal view of the horizontally-aligned active-site cleft. A substrate is bound N- to C-terminally from left (on the non-primed side of the cleft) to right (on the primed side), and the catalytic metal ion resides at the cleft bottom at roughly half width. This view enables us to see that most metalloendopeptidases are bifurcated into an upper and a lower sub-domain by the cleft, whose back is framed by a nearly horizontal "active-site helix." The latter comprises a short zinc-binding consensus sequence, either HEXXH or HXXEH, which provides two histidines to bind the single catalytic metal and the general-base/acid glutamate required for catalysis. In addition, an oblique "backing helix" is observed behind the active-site helix, and a mixed β-sheet of at least three strands is positioned in the upper sub-domain paralleling the cleft. The lowermost "upper-rim" strand of the sheet runs antiparallel to the substrate bound in the cleft and therefore contributes both to delimitating the cleft top and to binding of the substrate main-chain on its non-primed side through β-ribbon-like interactions. In contrast, in metalloexopeptidases, which chop off N- or C-terminal residues only, extensive binding on both sides of the cleft is not required and a different overall scaffold is generally observed. This consists of an αβα- sandwich, which is reminiscent of, but clearly distinct from, the archetypal α/β-hydrolase fold. Metalloexopeptidases have their active sites at the C-terminal end of a central, eight-stranded twisted β-sheet, and can contain one or two catalytic metal ions. As the zinc-binding site and the residues engaged in substrate binding and catalysis are mainly provided by loops connecting the β-sheet strands and the helices on either side, the respective standard orientations vary with respect to the position of the sheets. The standard orientation of eight prototypic MP structures is presented and discussed. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome. © 2011 Elsevier B.V. All rights reserved.

Mann K.,Max Planck Institute For Biochemie | Edsinger-Gonzales E.,University of California at Berkeley | Mann M.,Max Planck Institute For Biochemie
Proteome Science | Year: 2012

Background: Invertebrate biominerals are characterized by their extraordinary functionality and physical properties, such as strength, stiffness and toughness that by far exceed those of the pure mineral component of such composites. This is attributed to the organic matrix, secreted by specialized cells, which pervades and envelops the mineral crystals. Despite the obvious importance of the protein fraction of the organic matrix, only few in-depth proteomic studies have been performed due to the lack of comprehensive protein sequence databases. The recent public release of the gastropod Lottia gigantea genome sequence and the associated protein sequence database provides for the first time the opportunity to do a state-of-the-art proteomic in-depth analysis of the organic matrix of a mollusc shell. Results: Using three different sodium hypochlorite washing protocols before shell demineralization, a total of 569 proteins were identified in Lottia gigantea shell matrix. Of these, 311 were assembled in a consensus proteome comprising identifications contained in all proteomes irrespective of shell cleaning procedure. Some of these proteins were similar in amino acid sequence, amino acid composition, or domain structure to proteins identified previously in different bivalve or gastropod shells, such as BMSP, dermatopontin, nacrein, perlustrin, perlucin, or Pif. In addition there were dozens of previously uncharacterized proteins, many containing repeated short linear motifs or homorepeats. Such proteins may play a role in shell matrix construction or control of mineralization processes. Conclusions: The organic matrix of Lottia gigantea shells is a complex mixture of proteins comprising possible homologs of some previously characterized mollusc shell proteins, but also many novel proteins with a possible function in biomineralization as framework building blocks or as regulatory components. We hope that this data set, the most comprehensive available at present, will provide a platform for the further exploration of biomineralization processes in molluscs. © 2012 Mann et al licensee BioMed Central Ltd.

Mann K.,Max Planck Institute For Biochemie | Mann M.,Max Planck Institute For Biochemie
Proteome Science | Year: 2013

Background: Chicken eggshell mineralization is a prominent model for biomineralization not only because of its importance for avian reproduction but also because of the commercial interest associated with eggshell quality. An analysis and comparison of the protein constituents of eggshells of several species would contribute to a better understanding of the shell mineralization process. The recent publication of the turkey genome sequence now provides a basis for the in-depth analysis of the turkey eggshell proteome. Results: Proteomic analysis of turkey acid-soluble and acid-insoluble organic eggshell matrix yielded 697 identified proteins/protein groups. However, intensity-based absolute quantification (iBAQ) results indicated that the 47 most abundant identified proteins already constituted 95% of the total turkey eggshell matrix proteome. Forty-four of these proteins were also identified in chicken eggshell matrix previously. Despite these similarities there were important and unexpected differences. While ovocleidin-116 and ovocalyxin-36 were major proteins constituting approximately 37% of the identified proteome, other members of the group of so-called eggshell-specific proteins were not identified. Thus ovocalyxin-21 and ovocalyxin-32 were missing among matrix proteins. Conversely, major turkey eggshell proteins were not detected in chicken, such as the bone protein periostin, the mammalian counterpart of which is involved in many aspects of bone metabolism and which represented 10-11% of the total identified proteome. Conclusions: Even members of the same avian family show important differences in eggshell matrix composition and more studies on the proteome and the transcriptome level will be necessary to identify a common toolkit of eggshell mineralization and to work out species differences among functional eggshell protein sets and their role in eggshell production. © 2013 Mann and Mann; licensee BioMed Central Ltd.

Engelhardt H.,Max Planck Institute For Biochemie
Methods in Molecular Biology | Year: 2013

The ultrastructure of bacteria is only accessible by electron microscopy. Our insights into the architecture of cells and cellular compartments such as the envelope and appendages is thus dependent on the progress of preparative and imaging techniques in electron microscopy. Here, I give a short overview of the development and characteristics of methods applied for imaging (components of) the bacterial surface and refer to key investigations and exemplary results. In the beginning of electron microscopy, fixation of biological material and staining for contrast enhancement were the standard techniques. The results from freezeetching, metal shadowing and from ultrathin-sections of plastic-embedded material shaped our view of the cellular organization of bacteria. The introduction of cryo-preparations, keeping samples in their natural environment, and three-dimensional (3D) electron microscopy of isolated protein complexes and intact cells opened the door to a new dimension and has provided insight into the native structure of macromolecules and the in situ organization of cells at molecular resolution. Cryo-electron microscopy of single particles, together with other methods of structure determination, and cellular cryo-electron tomography will provide us with a quasi-atomic model of the bacterial cell surface in the years to come. © Springer Science+Business Media New York 2013.

Loading Max Planck Institute For Biochemie collaborators
Loading Max Planck Institute For Biochemie collaborators