ABSTRACT
Transfer RNA-mediated posttranslational protein modification by arginine has been demonstrated in vitro in axoplasm extruded from the giant axons of squid and in injured and regenerating vertebrate nerves. In nerve and axoplasm, the highest activity is found in a fraction of a 150,000 g supernatant containing high molecular weight protein/RNA complexes but lacking molecules of <5 kDa. Arginylation (and protein modification by other amino acids) is not found in more purified, reconstituted fractions. The data are interpreted as indicating that it is critical to recover the reaction components in high molecular weight protein/RNA complexes in order to maintain maximum physiological activity. The level of arginylation is greatest in injured and growing vertebrate nerves compared with intact nerves, suggesting a role for these reactions in nerve injury/repair and during axonal growth.
Subject(s)
Axons , Sciatic Nerve , Animals , Sciatic Nerve/physiology , Axons/metabolism , Amino Acids/metabolism , RNA, Transfer/metabolism , Vertebrates/metabolism , Decapodiformes/metabolismABSTRACT
Transfer RNA-mediated posttranslational protein modification by arginine has been demonstrated in vitro in axoplasm extruded from the giant axons of squid and in injured and regenerating vertebrate nerves. In nerve and axoplasm, the highest activity is found in a fraction of a 150,000 × g supernatant containing high molecular weight protein/RNA complexes but lacking molecules of <5 kDa. Arginylation (and protein modification by other amino acids) is not found in more purified, reconstituted fractions. The data are interpreted as indicating that it is critical to recover the reaction components in high molecular weight protein/RNA complexes in order to maintain maximum physiological activity. The level of arginylation is greatest in injured and growing vertebrate nerves compared with intact nerves, suggesting a role for these reactions in nerve injury/repair and during axonal growth.
Subject(s)
Arginine/metabolism , Axons/metabolism , Nerve Tissue Proteins/metabolism , Peripheral Nerve Injuries/metabolism , Protein Processing, Post-Translational , Spinal Nerves/metabolism , Animals , Cytoplasm/metabolism , Decapodiformes , Male , Optic Nerve/metabolism , Optic Nerve Injuries/metabolism , Rats , Sciatic Nerve/injuries , Sciatic Nerve/metabolismABSTRACT
Most graduate schools associated with medical schools offer programs leading to the PhD degree but pay little attention to master's programs. This is unfortunate because many university graduates who are interested specifically in biomedical rather than pure science fields need further education before making decisions on whether to enter clinical, research, education, or business careers. Training for these students is done best in a medical school, rather than a graduate university, environment and by faculty who are engaged in research in the biomedical sciences. Students benefit from these programs by exploring career options they might not have previously considered while learning about disease-related subjects at the graduate level. Graduate faculty can also benefit by being compensated for their teaching with a portion of the tuition revenue, funds that can help run their laboratories and support other academic expenses. Faculty also may attract talented students to their labs and to their PhD programs by exposing them to a passion for research. The graduate school also benefits by collecting masters tuition revenue that can be used toward supporting PhD stipends. Six-year outcome data from the program at Newark show that, on completion of the program, most students enter educational, clinical, or research careers and that the graduate school has established a new and significant stream of revenue. Thus, the establishment of a master's program in biomedical sciences that helps students match their academic abilities with their career goals significantly benefits students as well as the graduate school and its faculty.
