SEARCH · PubMed Health

Results for “cell deconvolution”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources

PubMed2001

From peptide libraries to optimized nonpeptide ligands in the search for S-farnesyltransferase inhibitors.

A complete 331,776-member library of tetrapeptides made of 24 amino acid building blocks was synthesized robotically on solid phase and subjected to a deconvolution based on the inhibitory potency of the sublibraries in a HPLC assay of the S-farnesyltransferase activity in vitro. One of the non-natural peptide and noncysteine-containing leads Nip-Trp-Phe-His (Nip=p-nitrophenyl-L-alanine) was optimized chemically to give a proteolytically stable pseudopeptide with a 200-fold potency compared with the original lead. The final compound was converted to the C-terminal ethyl ester: p-F-C6H4-CO(CH2)2-CO-Bta-D-Phepsi[CH2NH]His-OEt (Bta = benzothienyl-L-alanine) and shown to behave as a prodrug which was hydrolyzed back to the C-terminal acid following cell penetration. The method confirmed that several structurally original leads can be discovered in large libraries when deconvolution relies upon a highly specific assay and that these leads can be optimized by chemical modification to impart the final compound the desired pharmacological and pharmacokinetic properties.

Alkyl and Aryl Transferases↗

PubMed1999

Enterococcus faecalis bearing aggregation substance is resistant to killing by human neutrophils despite phagocytosis and neutrophil activation.

Enterococcus faecalis aggregation substance (AS) mediates efficient bacterium-bacterium contact to facilitate plasmid exchange as part of a bacterial sex pheromone system. We have previously determined that AS promotes direct, opsonin-independent binding of E. faecalis to human neutrophils (PMNs) via complement receptor type 3 and other receptors on the PMN surface. We have now examined the functional consequences of this bacterium-host cell interaction. AS-bearing E. faecalis was phagocytosed and internalized by PMNs, as determined by deconvolution fluorescence microscopy. However, these bacteria were not killed by PMNs, and internalized bacteria excluded propidium iodide, indicating intact bacterial membranes. Resistance to killing occurred despite activation of PMNs, as indicated by an increase in both functional and total surface Mac-1 expression, shedding of L-selectin, and an increase in PMN extracellular superoxide and phagosomal oxidant production. Deconvolution fluorescence microscopy also revealed that phagosomes containing AS-bearing bacteria were markedly larger than phagosomes containing opsonized E. faecalis, suggesting that some modification of phagosomal maturation may be involved in AS-induced resistance to killing. PMN phagosomal pH was significantly higher after ingestion of nonopsonized AS-bearing E. faecalis than after that of opsonized bacteria. The novel ability of AS to promote intracellular survival of E. faecalis inside PMNs suggests that AS may be a virulence factor used by strains of E. faecalis.

Animals↗

PubMed2005

Immunofluorescence deconvolution microscopy and image reconstruction of human defensins in normal and burned skin.

OBJECTIVE: The aim of this study was visualization and localization of the human antimicrobials human beta defensins 1, 2, and 3, neutrophil defensin alpha (human neutrophil peptide), and the cathelicidin LL-37 in normal and burned skin, and determination of the cell types in which these antimicrobials were localized. METHODS: Tissue sections were probed with antimicrobial antibodies, tagged with fluorescently labeled secondary antibodies, and subjected to fluorescence deconvolution microscopy and image reconstruction. Images were generated by stacking multiple-section scans, which were then volume rendered by rotating stacks 360 degrees about an axis, or modeled in 3 dimensions. RESULTS: This technique yields a definitive image, providing a rapid basis for further quantification and manipulation from a full 3-dimensional aspect. In normal skin, human beta defensin-1 was localized to the perinuclear region of keratinocytes; human beta defensin-2 was primarily localized to the stratum germinativum; human beta defensin-3 was found in dendritic cells of the stratum spinosum; human neutrophil peptide was randomly distributed in the papillary dermis; and LL-37 was concentrated in the stratum corneum and along ducts. In burned skin, in which keratinocytes are lost or destroyed, human beta defensin-1 was present in dermal glandular structures including hair shafts; human beta defensin-2 and human beta defensin-3 were found in the remaining keratin layers and glands of the lower dermis; human neutrophil peptide was primarily localized to hair shafts, though visible in residual keratin layers; and LL-37 was evident in very high concentrations in the epithelium of sweat ducts. CONCLUSION: We conclude via this technique that cells in the lower dermal and subdermal regions of burned skin synthesize antimicrobials after burn injury, and maintain something of a barrier against infection. This methodology is discussed and explained in this article.

Journal Article↗

PubMed1972

Direct determination of the structure of barium stearate multilayers by x-ray diffraction.

Diffraction of X-rays is recorded from barium stearate multilayer systems with from 2 to 60 double layers or unit cells. The generalized Patterson function P'(x) is calculated by an integral Fourier transform of observed intensity data from a specimen containing only two unit cells. The Patterson function P(0)(x) of a single unit cell is determined from P'(x) and the electron density distribution of a bimolecular leaflet is obtained by a deconvolution procedure of P(0)(x) after Hosemann and Bagchi. The electron density distribution is also calculated independently by a conventional Fourier synthesis with an experimentally established set of phases. The results of the two methods are consistent and fit a physical model of the bimolecular leaflet. A direct analysis, therefore, can be performed if diffraction is observed from multilayer systems with a small number of unit cells.

Barium↗

PubMed2005

Flow cytometric quantification of T cell proliferation and division kinetics in woodchuck model of hepatitis B.

Woodchucks infected with woodchuck hepatitis virus (WHV) represent the closest natural animal model to study the immunopathogenesis of liver injury caused by essentially noncytopathic, highly human specific hepatitis B virus (HBV). The importance of antiviral T cell response in induction of hepatitis and in control of HBV replication has been demonstrated. However, the understanding of how these responses contribute to the development of different immunomorphological forms of liver disease and their outcomes remain elusive. In this study, we established and standardized a flow cytometry assay using peripheral blood mononuclear cells labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) to assess WHV-specific and mitogen-driven T lymphocyte proliferative responses in woodchucks. The assay is of significantly greater sensitivity than the adenine incorporation assay currently used when applied to measure either WHV-specific T cell responses in acute (P < 0.001) and chronic (P < 0.03) viral hepatitis or those induced by mitogens in both healthy and WHV-infected animals. It also provides a new type of information, not previously available, characterizing the strength of woodchuck T cell proliferative reactivity by measuring cell division rates. The study shows that woodchuck PBMC labeled with CFSE exhibit light scatter and fluorescence profiles compatible to those of human PBMC, allowing quantitation and deconvolution of the flow cytometric data by applying the existing analytical softwares. The availability of this novel assay should facilitate a more precise and comprehensive evaluation of hepadnavirus-specific and generalized T cell responses in experimental WHV hepatitis.

Animals↗

PubMed1993

Ultrastructural appraisal of the multidrug resistance in K562 and LR73 cell lines from Fourier transform infrared spectroscopy.

Two different cell lines sharing the multidrug resistance (MDR) phenotype were investigated for 8 months by means of Fourier transform IR spectroscopy on cell smears. We studied (a) a human leukemic doxorubicin-sensitive K562 cell line, from which a doxorubicin-resistant K562 cell subline was subsequently derived; (b) a Chinese hamster LR73 drug-sensitive line, subsequently transfected with the expression plasmid pDREX4 containing the mdr1 gene, to produce a multidrug-resistant LR73 subline (MDR-LR73). The sensitivity of Fourier transform IR spectroscopy has allowed differentiation between sensitive and MDR phenotypes among the above lines, even in double blind studies. The MDR phenotype is characterized by three combined features in spectra: (a) a decrease in the intensities of the amide I and II bands; (b) a shoulder on the high wave numbers slope of the amide I bands; (c) a shift toward the high wave numbers of the amide II bands. Furthermore, computational treatment of Fourier transform IR spectra (deconvolution and Gaussian curve-fitting techniques), has evidenced, in MDR-K562 and MDR-LR73 cell sublines, a conformational change involving the same protein in both sublines. It is hypothesized that the protein implicated in the conformational change may be related to the MDR phenotype.

Animals↗

PubMed2001

Chromatin condensation and sensitivity of DNA in situ to denaturation during cell cycle and apoptosis--a confocal microscopy study.

The goal of this study was to construct high resolution 3D confocal images of regions of condensed and extended chromatin in cell nuclei and individual chromosomes. It has been shown previously that sensitivity of DNA in situ to denaturation correlates with chromatin condensation and varies during cell cycle and apoptosis. Thus, detection of DNA which was partially denatured in situ provided a means to image areas of condensed chromatin. DNA denaturation was detected using a metachromatic dye acridine orange (AO) which differentially stains single stranded (ss) and double-stranded (ds) DNA sections. Early studies of denaturability of cellular DNA utilized flow cytometry and standard fluorescence microscopy. These techniques could not reveal small local differences in DNA denaturability within cell nucleus or in individual chromosomes. For instance, it was not possible to detect the initial points of chromosome condensation in G2-phase of the division cycle or in apoptosis. In order to achieve this goal we have recently extended these studies by applying confocal microscopy. We investigated DNA denaturability in normal human fibroblasts and HL-60 leukemic cells, at different stages of cell cycle and apoptosis. Following removal of RNA and partial denaturation of DNA with acid cells were stained with AO. Green (530 nm) and red (640 nm) fluorescence (exc. 457 nm) of non-denatured and denatured DNA was imaged by confocal microscopy. Blind deconvolution was used to further improve the quality of 3D images. Photobleaching of AO fluorescence was minimized and a correction for chromatic aberration and register shift was implemented. Nuclei of interphase cells exhibited predominantly green fluorescence representing AO binding to ds DNA. Punctuate areas of red fluorescence representing AO binding to denatured DNA and most likely associated with local regions of condensed chromatin were also present in all interphase nuclei. The proportion of denatured DNA increased in cells entering mitosis. In prophase individual condensing chromosomes exhibited varied proportions of green and red fluorescence indicating different content of denatured chromatin. In some chromosomes bands of denatured and denaturation-resistant chromatin were clearly resolved. In metaphase and anaphase chromosomes exhibited red fluorescence along all length of their arms indicating the highest and uniform susceptibility to denaturation. In telophase chromosomes contained predominantly denaturation-resistant DNA again and denaturated regions were significantly less abundant. At cytokinesis some decondensing chromosomes were still resolved. At this stage almost all regions of denatured DNA were located close to nuclear envelope. These regions may correspond to pockets of heterochromatin reforming at nuclear periphery. In early apoptosis condensation of chromatin appeared to commence in several distinct regions within nucleus. Some apoptotic bodies contained condensed chromatin surrounding central regions of extended chromatin. At late stages of apoptosis the whole volume of apoptotic bodies was occupied by condensed chromatin.

Acridine Orange↗

PubMed2001

In situ detection of messenger RNA using digoxigenin-labeled oligonucleotides and rolling circle amplification.

The detection of specific RNA molecules in situ is routinely performed using haptenated probes, which are detected by either enzymatic amplification or direct fluorescence. A drawback of fluorescence labeling has been the reduced sensitivity relative to that of methods that use enzymes as signal generators. Reliable fluorescence detection methods often require the use of multiple oligonucleotide probes for each gene target. Here, we demonstrate that single haptenated DNA probes specific for actin mRNA may be detected in situ using antibody-coupled rolling circle amplification (immuno-RCA). This fluorescence-based detection method offers remarkable sensitivity due to the use of signal amplification and yet retains the ability to count hybridization signals as discrete objects. We demonstrate the detection of actin-specific immuno-RCA signals in the cytoplasm and use 3D image deconvolution of multiple z axis sections to show that there are hundreds of signals per cell. With some modifications, this method may be adaptable to the simultaneous detection of several RNA species, including low-copy-number mRNA.

5' Untranslated Regions↗

PubMed2001

Specificity in intracellular protein aggregation and inclusion body formation.

Protein aggregation is widely considered to be a nonspecific coalescence of misfolded proteins, driven by interactions between solvent-exposed hydrophobic surfaces that are normally buried within a protein's interior. Accordingly, abnormal interactions between misfolded proteins with normal cellular constituents has been proposed to underlie the toxicity associated with protein aggregates in many neurodegenerative disorders. Here we have used fluorescence resonance energy transfer and deconvolution microscopy to investigate the degree to which unrelated misfolded proteins expressed in the same cells coaggregate with one another. Our data reveal that in cells, protein aggregation exhibits exquisite specificity even among extremely hydrophobic substrates expressed at very high levels.

Cell Line↗

PubMed1987

[Accumulation of acridine amino derivatives by electron-dense granules in thrombocytes].

The uptake and release of dense bodies' content were studied using fluorescent amines. Real-time measurements of fluorescence spectra by a device developed on the basis of a multichannel optical analyzer and computer technique of spectrum deconvolution made it possible to investigate the kinetics of monoamine uptake and release in intact cells.

Acridine Orange↗

PubMed2004

Visceral fat in hypertension: influence on insulin resistance and beta-cell function.

Preferential visceral adipose tissue (VAT) deposition has been associated with the presence of insulin resistance in obese and diabetic subjects. The independent association of VAT accumulation with hypertension and its impact on insulin sensitivity and beta-cell function have not been assessed. We measured VAT and subcutaneous fat depots by multiscan MRI in 13 nondiabetic men with newly detected, untreated essential hypertension (blood pressure=151+/-2/94+/-2 mm Hg, age=47+/-2 years, body mass index [BMI]=28.4+/-0.7 kg x m(-2)) and 26 age-matched and BMI-matched normotensive men (blood pressure=123+/-1/69+/-2 mm Hg). Insulin secretion was measured by deconvolution of C-peptide data obtained during an oral glucose tolerance test, and dynamic indices of beta-cell function were calculated by mathematical modeling. For a similar fat mass in the scanned abdominal region (4.8+/-0.3 versus 3.9+/-0.3 kg, hypertensive subjects versus controls, P=0.06), hypertensive subjects had 60% more VAT than controls (1.6+/-0.2 versus 1.0+/-0.1 kg, P=0.003). Intrathoracic fat also was expanded in patients versus controls (45+/-5 versus 28+/-3 cm2, P=0.005). Insulin sensitivity was reduced (10.7+/-0.7 versus 12.9+/-0.4 mL x min(-1) x kg(ffm)(-1), P=0.006), and total insulin output was proportionally increased (64 [21] versus 45 [24] nmol x m(-2). h, median [interquartile range], P=0.01), but dynamic indices of beta-cell function (glucose sensitivity, rate sensitivity, and potentiation) were similar in the 2 groups. Abdominal VAT, insulin resistance, and blood pressure were quantitatively interrelated (rho's of 0.39 to 0.47, P<0.02 or less). In newly found, untreated men with essential hypertension, fat is preferentially accumulated intraabdominally and intrathoracically. Such visceral adiposity is quantitatively related to both height of blood pressure and severity of insulin resistance, but has no impact on the dynamics of beta-cell function.

Adipose Tissue↗

PubMed2005

Induction of rapid detachment in Shewanella oneidensis MR-1 biofilms.

Active detachment of cells from microbial biofilms is a critical yet poorly understood step in biofilm development. We discovered that detachment of cells from biofilms of Shewanella oneidensis MR-1 can be induced by arresting the medium flow in a hydrodynamic biofilm system. Induction of detachment was rapid, and substantial biofilm dispersal started as soon as 5 min after the stop of flow. We developed a confocal laser scanning microscopy-based assay to quantify detachment. The extent of biomass loss was found to be dependent on the time interval of flow stop and on the thickness of the biofilm. Up to 80% of the biomass of 16-h-old biofilms could be induced to detach. High-resolution microscopy studies revealed that detachment was associated with an overall loosening of the biofilm structure and a release of individual cells or small cell clusters. Swimming motility was not required for detachment. Although the loosening of cells from the biofilm structure was observed evenly throughout thin biofilms, the most pronounced detachment in thicker biofilms occurred in regions exposed to the flow of medium, suggesting a metabolic control of detachability. Deconvolution of the factors associated with the stop of medium flow revealed that a sudden decrease in oxygen tension is the predominant trigger for initiating detachment of individual cells. In contrast, carbon limitation did not trigger any substantial detachment, suggesting a physiological link between oxygen sensing or metabolism and detachment. In-frame deletions were introduced into genes encoding the known and putative global transcriptional regulators ArcA, CRP, and EtrA (FNR), which respond to changes in oxygen tension in S. oneidensis MR-1. Biofilms of null mutants in arcA and crp were severely impacted in the stop-of-flow-induced detachment response, suggesting a role for these genes in regulation of detachment. In contrast, an DeltaetrA mutant displayed a variable detachment phenotype. From this genetic evidence we conclude that detachment is a biologically controlled process and that a rapid change in oxygen concentration is a critical factor in detachment and, consequently, in dispersal of S. oneidensis cells from biofilms. Similar mechanisms might also operate in other bacteria.

Base Sequence↗

PubMed1999

The ADP-ribosylation factor (ARF)-related GTPase ARF-related protein binds to the ARF-specific guanine nucleotide exchange factor cytohesin and inhibits the ARF-dependent activation of phospholipase D.

ADP-ribosylation factor-related protein (ARP) is a membrane-associated GTPase with remote similarity to the family of ADP-ribosylation factors (ARF). In a yeast two-hybrid screen designed to identify proteins interacting with ARP, we isolated a partial cDNA of the ARF-specific guanine nucleotide exchange factor mSec7-1/cytohesin encoding its N terminus and most of the Sec7 domain (codons 1-200). ARP and ARP-Q79L (GTPase-negative ARP) exhibited a higher affinity to mSec7-1-(1-200) than ARP-T31N (nucleotide exchange-defective ARP) in the two-hybrid assay. Similarly, full-length [35S]mSec7-1/cytohesin was specifically adsorbed to glutathione-Sepharose loaded with glutathione S-transferase (GST)-ARP-Q79L, GST-ARP, or GST-ARP-T31N, the latter exhibiting the lowest binding affinity. Overexpression of ARP-Q79L, but not of ARP-T31N, in COS-7 cells reduced the fluorescence from co-expressed green fluorescent protein fused with mSec7-1/cytohesin or mSec7-2/ARNO in plasma membranes as detected by deconvolution microscopy. Recombinant ARP and ARP-Q79L, but not ARP-T31N, inhibited the phospholipase D (PLD) activity stimulated by mSec7-2/ARNO and ARF in a system of isolated membranes. Furthermore, transfection of HEK-293 cells with ARP or ARP-Q79L, but not ARP-T31N, inhibited the muscarinic acetylcholine receptor-3 induced PLD stimulation and translocation of ARF from cytosol to membranes. These data suggest that the GTP-bound form of ARP specifically binds mSec7-1/cytohesin, and that ARP may be involved in a pathway inhibiting the ARF-controlled activity of PLD.

ADP-Ribosylation Factors↗

PubMed2005

Beta-cell dysfunction and low insulin clearance in insulin-resistant human immunodeficiency virus (HIV)-infected patients with lipodystrophy.

OBJECTIVE: To obtain a better understanding of the physiological aspects of glucose homeostasis in human immunodeficiency virus (HIV)-infected patients with lipodystrophy, we evaluated separately beta-cell function and insulin sensitivity after an oral glucose load. DESIGN: Beta-cell function was investigated during an oral glucose tolerance test (OGTT) (75 g, 180 min) in 16 lipodystrophic HIV-infected patients and in 15 age- and weight-matched nonlipodystrophic HIV-infected patients. All participants were sedentary Caucasian males, who were on highly active antiretroviral therapy with no history of diabetes mellitus or impaired glucose tolerance. Prehepatic insulin secretion rates were estimated by deconvolution of C-peptide concentrations. A composite measure of insulin sensitivity was derived from the OGTT. RESULTS: Beta-cell secretory capacity (i.e. the rate of change in insulin secretion per unit change in glucose concentration) was similar in lipodystrophic and nonlipodystrophic patients (6.2 +/- 1.0 mU kg(-1) min(-1) mg(-1) dl vs. 5.4 +/- 0.4, P > 0.4), but insulin sensitivity was reduced by 61% in lipodystrophic patients (P < 0.004). The disposition index (insulin capacity multiplied with insulin sensitivity) and insulin clearance rate were reduced in lipodystrophic patients (-55%, P < 0.003 and -31%, P < 0.004). Insulin clearance rate correlated strongly with insulin sensitivity (r = 0.82, P < 0.001). More lipodystrophic than nonlipodystrophic patients exhibited impaired glucose tolerance and diabetes mellitus (63%vs. 20%, P < 0.05). CONCLUSIONS: Our data support the concept that impaired glucose tolerance in lipodystrophic HIV-infected patients relates to a failure of the beta-cells to fully compensate for decrements in insulin sensitivity despite simultaneous reduction in insulin clearance.

Adult↗

PubMed1984

[Measurement of mean retention times of 99mTc-labeled HSA-millimicrospheres in the liver--clinical results in patients with operated breast cancer].

Human serum albumin millimicrospheres labeled with 99mTc-pertechnetate were used for evaluation of their mean retention time in the hepatic RES cells. For this purpose the retention function was derived from the liver time-activity curves by deconvolution analysis. Measurements in 50 patients with operated breast cancer revealed significantly shorter retention times in patients with extrahepatic metastases in comparison with patients without evidence of metastases or recurrences. Discriminant analysis of the retention times combined with other investigated parameters such as relative organ size and extraction fraction of the liver and spleen, age, weight and height of the patient, proved the method to be diagnostically valuable. In the examined group of patients metastases could be demonstrated with a sensitivity of 100% and a specificity of 92%.

Breast Neoplasms↗

PubMedDate not supplied

Software for 3-D reconstruction from images of oblique sections through 3-D crystals.

Oblique section reconstruction can produce a 3-D image from electron micrographs of a sectioned crystal when the orientation of the section plane is not aligned with the principal planes of the unit cell. We describe here the reconstruction protocol and the specialized computer software for a Fourier space method that can extract 3-D information from 2-D projection images of oblique sections. The protocol encompasses correction for image defects and image distortions, determination and refinement of reciprocal lattices, calculation of the crystal orientation in 3-D space, extraction of periodic information, alignment in Fourier space, determination and deconvolution of section thickness, and calculation of structure factors of the original crystal. A 3-D map of the unit cell can then be computed by standard crystallographic procedures. Oblique section reconstruction provides an alternative to tomography for 3-D imaging of crystalline objects with large unit cells. The method provides an excellent means of obtaining a 3-D transform using electron microscopy for comparison with X-ray diffraction data from native specimens.

Computer Simulation↗

PubMed2006

Statistical deconvolution of enthalpic energetic contributions to MHC-peptide binding affinity.

BACKGROUND: MHC Class I molecules present antigenic peptides to cytotoxic T cells, which forms an integral part of the adaptive immune response. Peptides are bound within a groove formed by the MHC heavy chain. Previous approaches to MHC Class I-peptide binding prediction have largely concentrated on the peptide anchor residues located at the P2 and C-terminus positions. RESULTS: A large dataset comprising MHC-peptide structural complexes was created by re-modelling pre-determined x-ray crystallographic structures. Static energetic analysis, following energy minimisation, was performed on the dataset in order to characterise interactions between bound peptides and the MHC Class I molecule, partitioning the interactions within the groove into van der Waals, electrostatic and total non-bonded energy contributions. CONCLUSION: The QSAR techniques of Genetic Function Approximation (GFA) and Genetic Partial Least Squares (G/PLS) algorithms were used to identify key interactions between the two molecules by comparing the calculated energy values with experimentally-determined BL50 data. Although the peptide termini binding interactions help ensure the stability of the MHC Class I-peptide complex, the central region of the peptide is also important in defining the specificity of the interaction. As thermodynamic studies indicate that peptide association and dissociation may be driven entropically, it may be necessary to incorporate entropic contributions into future calculations.

Binding Sites↗

PubMed2000

SpoIIB localizes to active sites of septal biogenesis and spatially regulates septal thinning during engulfment in bacillus subtilis.

A key step in the Bacillus subtilis spore formation pathway is the engulfment of the forespore by the mother cell, a phagocytosis-like process normally accompanied by the loss of peptidoglycan within the sporulation septum. We have reinvestigated the role of SpoIIB in engulfment by using the fluorescent membrane stain FM 4-64 and deconvolution microscopy. We have found that spoIIB mutant sporangia display a transient engulfment defect in which the forespore pushes through the septum and bulges into the mother cell, similar to the situation in spoIID, spoIIM, and spoIIP mutants. However, unlike the sporangia of those three mutants, spoIIB mutant sporangia are able to complete engulfment; indeed, by time-lapse microscopy, sporangia with prominent bulges were found to complete engulfment. Electron micrographs showed that in spoIIB mutant sporangia the dissolution of septal peptidoglycan is delayed and spatially unregulated and that the engulfing membranes migrate around the remaining septal peptidoglycan. These results demonstrate that mother cell membranes will move around septal peptidoglycan that has not been completely degraded and suggest that SpoIIB facilitates the rapid and spatially regulated dissolution of septal peptidoglycan. In keeping with this proposal, a SpoIIB-myc fusion protein localized to the sporulation septum during its biogenesis, discriminating between the site of active septal biogenesis and the unused potential division site within the same cell.

Bacillus subtilis↗