Biomedical subjects

D S Joy

Publications and source records attributed to D S Joy.

5 recordsLinked to original sources

PubMed1998

Effect of carbohydrate position on lysosomal transport of procathepsin L.

To study the role of carbohydrate in lysosomal protein transport, we engineered two novel glycosylation signals (Asn-X-Ser/Thr) into the cDNA of human procathepsin L, a lysosomal acid protease. We constructed six mutant cDNAs encoding glycosylation signals at mutant sites Asn-138, Asn-175, or both sites together, in the presence or absence of the wild-type Asn-204 site. We stably transfected wild-type and mutant cDNAs into NIH3T3 mouse fibroblasts and then used species-specific antibodies to determine the glycosylation status, phosphorylation, localization, and transport kinetics of recombinant human procathepsin L containing one, two, or three glycosylation sites. Both novel glycosylation sites were capable of being glycosylated, although Asn-175 was utilized only 30-50% of the time. Like the wild-type glycosylation at Asn-204, carbohydrates at Asn-138 and Asn-175 were completely sensitive to endoglycosidase H, and they were phosphorylated. Mutant proteins containing two carbohydrates were capable of being delivered to lysosomes, but there was not a consistent relationship between the efficiency of lysosomal delivery and carbohydrate content of the protein. Pulse-chase labeling revealed a unique biosynthetic pattern for proteins carrying the Asn-175 glycosylation sequence. Whereas wild-type procathepsin L and mutants bearing carbohydrate at Asn-138 appeared in lysosomes by about 60 min, proteins with carbohydrate at Asn-175 were processed to a lysosome-like polypeptide within 15 min. Temperature shift, brefeldin A, and NH4Cl experiments suggested that the rapid processing did not occur in the endoplasmic reticulum and that Asn-175 mutants could interact with the mannose 6-phosphate receptor. Taken together, our results are consistent with the interpretation that Asn-175 carbohydrate confers rapid transport to lysosomes. We may have identified a recognition domain in procathepsin L that is important for its interactions with the cellular transport machinery.

3T3 Cells↗

PubMed1997

Nucleoprotein-based nanoscale assembly.

A system for addressing in the construction of macromolecular assemblies can be based on the biospecificity of DNA (cytosine-5) methyltransferases and the capacity of these enzymes to form abortive covalent complexes at targeted 5-fluorocytosine residues in DNA. Using this system, macromolecular assemblies have been created using two representative methyltransferases: M-HhaI and M x MspI. When 5-fluorocytosine (F) is placed at the targeted cytosine in each recognition sequence in a synthetic oligodeoxynucleotide (GFGC for M x HhaI or FCGG for M x MspI), we show that the first recognition sequence becomes an address for M x HhaI, while the second sequence becomes an address for M x MspI. A chimeric enzyme containing a dodecapeptide antigen linked to the C terminus of M-HhaI retained its recognition specificity. That specificity served to address the linked peptide to the GFGC recognition site in DNA. With this assembly system components can be placed in a preselected order on the DNA helix. Axial spacing for adjacent addresses can be guided by the observed kinetic footprint of each methyltransferase. Axial rotation of the addressable protein can be guided by the screw axis of the DNA helix. The system has significant potential in the general construction of macromolecular assemblies. We anticipate that these assemblies will be useful in the construction of regular protein arrays for structural analysis, in the construction of protein-DNA systems as models of chromatin and the synaptonemal complex, and in the construction of macromolecular devices.

Base Sequence↗

PubMed1990

A multidimensional approach for selecting child care workers.

A multidimensional selection battery was designed to predict a variety of criteria important in the selection of child care workers. The battery assesses constructs related to honesty, violence, substance abuse, emotional stability and safety. A series of studies were used to test the validity of the selection battery. Scores on the test battery were compared with those from three alternative selection procedures to define the measured constructs. Three additional studies show the relation of scores on the selection battery and the behavior of child care workers. The test battery was correlated with the job performance of child care workers and identified adults convicted for sexual offenses against minors.

Adult↗

PubMed1989

Complex interactions between pregnenolone sulfate and the t-butylbicyclophosphorothionate-labeled chloride ionophore in rat brain.

Detailed studies of the interactions between the 'neuroactive' steroid, pregnenolone sulfate (PS), and the gamma-aminobutyric acid (GABA)/benzodiazepine receptor-linked chloride ionophore (GBRC) labeled by [35S]t-butylbicyclophosphorothionate ([35S]TBPS) in the rat brain reveal a site of action allosteric to the TBPS-labeled site as demonstrated by the ability of PS to accelerate TBPS-initiated dissociation of [35S]TBPS. In contrast to previous findings, PS modulates [35S]TBPS binding in a GABA 'agonist'-like fashion with micromolar potencies. The role of PS in the regulation of neuronal excitability through the GBRC is questioned, based upon the observation that brain concentrations of PS are 2-3 orders of magnitude less than that necessary for the modulation of chloride conductance in vitro.

Animals↗

PubMed1981

The maintenance of order on an adolescent inpatient unit: an analysis of work on the evening shift.

This paper attempts to explain a subset of aggressive interactions between a group of staff members and male adolescent inpatients in a large residential mental health facility. The interactions center around staff use of physical confrontation as a method of managing contranormative or noncompliant patient behaviors. My explanation is based on the notion that certain system variables--i.e., the importance for some staff to demonstrate their competence as effective crisis managers--may promote and support a staff culture of confrontation. Four concepts are used to analyze this culture of confrontation: (a) shift style, (b) shift role, (c) staff values, and (d) group character. In making use of these concepts, the analysis is able to incorporate aspects of aggression in institutional settings which remain anomalous in many accepted theories and to indicate a possible means of reducing staff confrontation. Evidence for this view is derived mainly from participant observation data.

Adolescent↗