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S R Goodman

Publications and source records attributed to S R Goodman.

At least 73 records · Page 4Linked to original sources
PubMed1987

The 180-kD component of the neural cell adhesion molecule N-CAM is involved in cell-cell contacts and cytoskeleton-membrane interactions.

N-CAM180, the molecular form of the three neural cell adhesion molecules (N-CAM) with the largest cytoplasmic domain, is accumulated at sites of cell-cell contact (cell bodies, neurites, growth cones) in cultures of neuroblastoma and cerebellum. At these sites the cytoskeleton-membrane linker protein brain spectrin and actin are also accumulated. Brain spectrin copurifies with N-CAM180 by immunoaffinity chromatography and binds specifically to N-CAM180 but not to N-CAM140 or N-CAM120 in a solid-phase binding test. These observations indicate an association of N-CAM180 with the cytoskeleton in vivo. This association may underlie the reduced lateral mobility of N-CAM180 in the surface membrane compared to N-CAM140 (Pollerberg et al. 1986). Together with the fact that N-CAM180 is only expressed after termination of neuron migration in vivo (Persohn and Schachner, unpublished) these results suggest a role for N-CAM180 in stabilization of cell contacts.

Animals↗
PubMed1987

Immunological detection of high molecular weight proteins by gel and blot overlay.

The sensitivity and specificity of the gel overlay and western blot methods of immunodetection are compared for spectrins, typical high molecular weight proteins. The gel overlay method is more sensitive and specific for the immunodetection of brain spectrin (240/235) and rbc spectrin. As the western blot technique will remain the method of choice for many applications because of its relative speed, we discuss methods for optimizing its sensitivity and selectivity.

Animals↗
PubMed1987

Spectrin isoforms in mammalian brain.

In this brief review we discuss the structure, location, developmental expression and potential functions of the spectrin isoforms [spectrin(240/235) and spectrin (240/235E)] within mammalian brain. We also contrast the structure and location of mammalian and avian brain spectrin isoforms.

Animals↗
PubMed1987

Amelin and synapsin I are 4.1 related spectrin binding proteins in brain.

How do synaptic vesicles move towards the presynaptic plasma membrane, fuse with that membrane, and release their contents during synaptic transmission? The answers to these questions at the molecular level are just beginning to be understood. Synapsin I is a neuron specific phosphoprotein that is associated with the cytoplasmic surface of synaptic vesicles. During synaptic transmission, the translocation of the synaptic vesicles to the presynaptic membrane of the neuron is thought to be mediated through changes in the phosphorylation state of synapsin I. It has been suggested that synapsin I is a spectrin binding protein related to the erythrocyte cytoskeletal protein 4.1, which binds to the terminal ends of the erythrocyte spectrin tetramer. The interaction of synapsin I (through brain spectrin) with the neuronal cytoskeleton may be essential for regulating the movement of synaptic vesicles towards the presynaptic plasma membrane. In addition, we have identified another protein in brain that is immunologically and structurally more closely related to erythrocyte 4.1 than is synapsin I. This protein, termed amelin, is localized in the cell body and dendrites of the neuron, whereas synapsin I is found exclusively in the synaptic terminals, suggesting that there is a family of erythrocyte 4.1 related proteins present in brain with distinct subcellular distribution and functions.

Animals↗
PubMed1987

Spectrin expression during mammalian brain ontogeny.

At least 2 distinct spectrin subtypes, brain spectrin(240/235) and brain spectrin(240/235E), are contained in the mammalian brain. Evidence that these subtypes are differentially expressed during mouse brain development is reviewed. Brain spectrin(240/235) is detected in fetal brain tissues, and increases 2-fold to adult levels. This subtype is enriched in the cortical cytoplasm of germinative neural cells, and is also associated with fibers resembling axons in the fetus. Brain spectrin(240/235E), a brain subtype specifically detected with antibodies to red blood cell spectrin, is below the limits of detection in the fetal and neonatal brain rapidly increases in concentration during the second postnatal week. Brain spectrin(240/235E) is found in the cell body and dendrites of differentiating neurons and glial cells, but is not expressed in mitotic cells. This subtype is especially prominent in granules cells of the cerebellum and dentate gyrus. The potential function of these spectrin subtypes during neuro-ontogeny is discussed.

Animals↗
PubMed1987

Structural and functional relationship of red blood cell protein 4.1 to synapsin I.

It has been suggested that the neuron specific protein synapsin I is closely related to red blood cell (rbc) protein 4.1. A systematic comparison of the structural and functional properties of rbc protein 4.1 and synapsin I has been carried out. There is approximately a three order of magnitude difference in cross reactivity of synapsin I with rbc 4.1 antiserum vs. synapsin I antiserum, as determined by a competitive quantitative dot assay. Two-dimensional chymotryptic iodopeptide mapping analysis demonstrated limited peptide homology (approximately 34% spot overlap) between rbc 4.1 and synapsin I. Dephosphorylated synapsin I binds saturably to brain spectrin (240/235) with an estimated dissociation constant (Kd) of 700 nM and a maximal binding capacity of 4 mol synapsin I/mol spectrin tetramer, similar to the affinity and stoichiometry of 4.1 binding to rbc spectrin. Synapsin I was found to bind to the terminal ends of the brain spectrin tetramer by low-angle rotary shadowing, analogous to 4.1 binding to rbc spectrin. In summary, synapsin I is structurally and immunologically distinct from rbc 4.1, yet shares functional similarities with rbc 4.1 with respect to its spectrin binding characteristics.

Animals↗
PubMed1987

Opioid receptors and endogenous opioids in diverse human and animal cancers.

Receptor binding studies demonstrated specific high-affinity, saturable binding of a number of opioid ligands to a wide variety of neural and nonneural human and animal tumors. Radioimmunoassays revealed the presence of beta-endorphin and methionine-enkephalin in these tumors. Both methionine- and leucine-enkephalin were detected in tumor tissue by immunocytochemistry, with immunoreactivity related to the cortical cytoplasm of tumor cells, but not to cell nuclei. Endogenous opioids and receptors were found in benign and malignant tumors representative of ectodermal, mesodermal, and endodermal origin. Receptors and endogenous opioid peptides were present in tumors from many different species, including those transplanted into nude mice. These results suggest that opioid receptors and endogenous opioids are fundamental features of human and animal cancers.

Animals↗
PubMed1987

Amelin: a 4.1-related spectrin-binding protein found in neuronal cell bodies and dendrites.

An immunoreactive, structural, and functional analog of erythrocyte protein 4.1 is present in neuronal cell bodies and dendrites. Other investigators have described the isolation of a 4.1 analog in brain with structural characteristics suggesting that its identity was synapsin I, a neuronal phosphoprotein localized in the presynaptic terminal in association with small synaptic vesicles. In this report we demonstrate that the cell body/dendritic form of brain protein 4.1, which we have named amelin, is distinct from that of synapsin I on the basis of subcellular localization, migration in 2-dimensional gel electrophoresis, and structural criteria. We also demonstrate that amelin, like synapsin I, can bind brain spectrin on nitrocellulose paper. Neither amelin nor synapsin I binds calmodulin, as determined by a blot binding assay. We hypothesize that there exists in brain a family of 4.1-related proteins with distinct subcellular localization and function.

Animals↗
PubMed1987

Brain spectrin(240/235) and brain spectrin(240/235E): differential expression during mouse brain development.

Mouse brain contains at least 2 distinct spectrin subtypes: brain spectrin(240/235) and brain spectrin(240/235E) (Riederer et al., 1986). In this study, we demonstrate that these subtypes are differentially expressed during mouse brain development. Brain spectrin(240/235) can be detected in fetal tissue and increases 2-fold during brain development. This subtype is enriched in the cortical cytoplasm of germinative neural cells and is also found in fibers resembling axons as early as fetal life. Brain spectrin(240/235E), which is specifically detected with antibodies to red blood cell spectrin, is below the limits of detection in fetal and neonatal brain but rapidly increases in concentration during the second postnatal week. Brain spectrin(240/235E) is confined to the cell body and dendrites of differentiating neurons and to glial cells but is not expressed in mitotic cells. This subtype is most prominent in granule cells of the cerebellum and dentate gyrus in the hippocampus.

Animals↗
PubMed1986

A rapid purification of synapsin I: a neuron specific spectrin binding protein.

We have developed a one chromatographic step isolation protocol for the neuron specific protein synapsin I. This procedure results in a yield of 80 micrograms/g brain, which is ten fold better than the highest yield yet reported for this protein. The authenticity of the synapsin I isolated by this procedure is demonstrated by comigration with authentic synapsin I on SDS-polyacrylamide gels, crossreactivity with antibody specific against synapsin I, and nearly identical two dimensional chrymotryptic iodopeptide maps of authentic synapsin I and the protein purified by this protocol. Synapsin I isolated by this procedure retains its functional properties, demonstrated by the ability of synapsin I to stimulate the formation of a brain spectrin(240/235)/synapsin I/F-actin ternary complex as determined by a low shear falling ball viscometry assay. This novel protocol therefore has the advantage of being a rapid, high yield procedure that retains the functional properties of synapsin I.

Actins↗
PubMed1986

Spectrin expression in neuroblastoma cells.

Mouse neuroblastoma cells express a spectrin-related molecule containing 240 kDal (kiloDalton) and 235 kDal subunits in a 1:1 ratio. The 240 kDal and 235 kDal subunits are nearly identical to the alpha and beta subunits respectively of brain spectrin by two dimensional chymotryptic peptide mapping analysis. The neuroblastoma cells do not express a measureable quantity of a red blood cell (rbc)-type spectrin molecule. Neuroblastoma spectrin has been localized throughout the cell body, and neurites of these cells by indirect immunofluorescence studies. As neuroblastoma cells are homogeneous, neuron-like, available in large quantity, and synthesize a single variant of spectrin which is closely related to brain spectrin(240/235), it is the best available model system for the study of the synthesis, assembly and turnover of a neuronal spectrin subtype.

Animals↗
PubMed1986

Brain spectrin(240/235) and brain spectrin(240/235E): two distinct spectrin subtypes with different locations within mammalian neural cells.

Adult mouse brain contains at least two distinct spectrin subtypes, both consisting of 240-kD and 235-kD subunits. Brain spectrin(240/235) is found in neuronal axons, but not dendrites, when immunohistochemistry is performed with antibody raised against brain spectrin isolated from enriched synaptic/axonal membranes. A second spectrin subtype, brain spectrin(240/235E), is exclusively recognized by red blood cell spectrin antibody. Brain spectrin(240/235E) is confined to neuronal cell bodies and dendrites, and some glial cells, but is not present in axons or presynaptic terminals.

Animals↗
PubMed1986

The neural cell spectrin skeleton: a review.

The discovery of nonerythroid spectrin (Goodman et al., Proc. Natl. Acad. Sci. USA 78: 7570-7574, 1981) has generated interest equivalent to that occurring upon the identification of nonmuscle actin and myosin. Brain spectrin has become the best-studied member of the nonerythroid spectrin family of molecules. In this review, we discuss the structure and functional interactions of brain spectrin, as a prelude to attempting to resolve what are some of the more controversial questions in the field. We finish with a discussion of what may be the most profitable directions for future research.

Animals↗
PubMed1986

Occurrence of spectrin-like protein in Y-1 adrenal tumor cells.

With the aid of two monospecific antibodies raised in rabbits (antimouse erythrocyte spectrin and antimouse brain spectrin), the presence of a spectrin-like protein was demonstrated in mouse adrenal tumor (Y-1) cells. Y-1 cells contain two large polypeptides, with mol wt characteristic of nonerythroid spectrin alpha- and beta-subunits (240,000 and 235,000). When proteins from plasma membranes of Y-1 cells were electrophoretically transferred to a nitrocellulose membrane, two polypeptides with mol wt of 240,000 and 225,000 were specifically stained with antimouse erythrocyte (rbc) spectrin immunoglobulin G (IgG). The rbc spectrin antibody was used to immunoprecipitate Y-1 spectrin from a neutral detergent (physiological ionic strength) cell extract. The 240,000 (alpha)- and 235,000 (beta)-dalton polypeptides were immunoprecipitated in a 1:1 molar ratio, despite the fact that the antibody recognizes only the alpha-subunit. Two-dimensional chymotryptic peptide-mapping analysis indicated that the 240,000- and 235,000-dalton subunits of Y-1 adrenal tumor spectrin are structurally unique and share limited homology with mouse rbc spectrin alpha- and beta-subunits, but are nearly identical to the mouse brain spectrin 240,000-dalton alpha-subunit and 235,000-dalton beta-subunit. Indirect immunofluorescence with anti-rbc or antibrain spectrin IgG and goat antirabbit IgG conjugated with rhodamine demonstrated intense staining at the plasma membrane and throughout the cytoplasm of Y-1 cells, with little staining within the nucleus.

Adrenal Gland Neoplasms↗
PubMed1986

Spectrin subtypes in mammalian brain: an immunoelectron microscopic study.

Spectrin is a major cytoskeletal component of the brain. At least 2 distinct spectrin subtypes are found in mammalian brain: brain spectrin(240/235) and brain spectrin(240/235E). In the present study spectrin subtypes were localized in the adult mouse brain by immunoelectron microscopy using antibodies that recognize each subtype. Brain spectrin(240/235E) was concentrated in neuronal cell bodies, dendrites, and postsynaptic terminals. It was also prominently associated with the plasma membrane, microtubules, filaments, mitochondria, endoplasmic reticulum, and nuclear envelope, and it appeared to interconnect structural elements within the cell. Brain spectrin(240/235E) also was localized to the plasma membrane, nuclear envelope, and cytoplasmic organelles of glial cell bodies. Brain spectrin(240/235) was detected in axons and presynaptic elements, where it was associated with the plasma membrane, microtubules, filaments, synaptic vesicles, and mitochondria. These results show that spectrin is distributed throughout the cytoplasm of neural cells, the location of spectrin is dependent on subtype, and the cytoplasmic surface of plasma membrane and organelles contains an extensive and intricate spectrin meshwork.

Animals↗
PubMed1985

Clinical computing in a teaching hospital.

This report describes a hospital-wide clinical computing system that permits physicians, nurses, medical students, and other health workers to retrieve data from the clinical laboratories; to look up reports from the departments of radiology and pathology; to look up demographic data and outpatient visits; to look up prescriptions filled in the outpatient pharmacy; to perform bibliographic retrieval of the MEDLINE data base; to read, write, retract, edit, and forward electronic mail; and to request delivery of a patient's chart. During a one-week study period, from 300 video display terminals located throughout the hospital, 818 patient care providers used a common registry of 539,000 patients to look up clinical and laboratory data 16,768 times; 477 other hospital workers used the patient registry 46,579 times. In a separate study of 586 health care providers, 470 (80 per cent) indicated that they used computer terminals "most of the time" to look up laboratory results; in contrast, 48 (8 per cent) preferred printed reports. Of 545 hospital workers, 440 (81 per cent) indicated that the computer terminals definitely or probably made their work more accurate, and 452 (83 per cent) indicated that terminals enabled them to work faster. The large amount of use by clinicians and their judgment that the computer has been so helpful to them suggests that a reliable, comprehensive, and easy-to-use computer system can contribute substantially to the quality of patient care.

Boston↗
PubMed1985

Identification of a spectrin-like protein in Sertoli cells.

Sertoli cells prepared from rats ages 15 and 25 days were shown to contain a spectrin-like protein. Indirect immunofluorescence with monospecific antimouse erythrocyte immunoglobulin G (IgG) and with monospecific antimouse brain spectrin IgG revealed specific staining in Sertoli cells. Both antibodies precipitated two spectrin-like peptides of 240,000 and 235,000 daltons from cells solubilized with octyl glucoside. Proteins from Sertoli cell membranes were separated by electrophoresis on polyacrylamide gels containing sodium dodecyl sulfate and electrophoretically transferred to nitrocellulose membrane. Incubation of nitrocellulose membrane with either of the two antibodies, followed by horseradish peroxidase conjugated to second antibody, revealed only the larger, or alpha, spectrin subunit (Western blots). Both antibodies were used to provide immunoautoradiographic identification of the spectrin-like protein. In this procedure, spectrin and Sertoli cell membranes were shown to compete with [125I]-labeled spectrin from mouse erythrocytes for binding to antimouse erythrocyte spectrin IgG. Finally, two-dimensional proteolytic mapping of the 240,000- and 235,000-dalton peptides demonstrated limited spot homology with rat erythrocyte spectrin. However, subcellular fractions from Sertoli cells all contained a spectrin-like protein showing high homology from fraction to fraction. It is concluded that Sertoli cells contain a spectrin-like protein that is seen in cell fractions prepared by centrifugation, i.e., mitochondria, microsomes, nuclei, cytoplasm, and plasma membranes. Although homology with spectrin from erythrocytes or brain is not seen in peptide maps, the alpha subunit shares antigenic determinants with spectrin from erythrocytes. The beta subunit is believed to be precipitated by antispectrin as the result of binding to the alpha subunit, since the beta subunit shows no detectable antigenic homology with that of spectrin.

Animals↗