¹ From the Division of Biology, California Institute of Technology, Pasadena, California 91109

Biosynthesis of the egg-laying hormone in the bag cell neurons of Aplysia californica was studied. Bag cells were incubated with leucine-³H in vitro for 30 min and rinsed for variable periods of time in a chase medium. The distribution of incorporated label among proteins within the cells was assayed by electrophoresis of an homogenate on sodium dodecyl sulfate polyacrylamide gels. Results from rinse times shorter than 30 min revealed that the predominant synthetic product is a 25,000 dalton protein. With longer rinse times, this species was reduced and two species of lower molecular weight became prominent. This redistribution of radioactivity was quantitative and was not prevented by inhibition of protein synthesis during the rinse. A 10°C reduction in temperature (from 15°C) blocked the redistribution. These data are interpreted to indicate that the 25,000 dalton molecule is a precursor which is cleaved enzymatically to yield two lower molecular weight products. One product is a 12,000 dalton molecule which remains in the cell bodies. The other is a molecule of <10,000 daltons which is exported from the somata into the neurohemal regions of the connective tissue. Perfusion of these regions with high [K⁺] medium results in the release of this product into the medium. It is concluded that this product is the 6000 dalton egg-laying hormone (ELH).

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				A. Y. Hung and N. S. Magoski Activity-Dependent Initiation of a Prolonged Depolarization in Aplysia Bag Cell Neurons: Role for a Cation Channel J Neurophysiol, March 1, 2007; 97(3): 2465 - 2479. [Abstract] [Full Text] [PDF]

				L. McAllister, R. Scheller, E. Kandel, and R Axel In situ hybridization to study the origin and fate of identified neurons Science, November 18, 1983; 222(4625): 800 - 808. [Abstract] [PDF]

				A.C. Mahon and R.H. Scheller The Molecular Basis of a Neuroendocrine Fixed Action Pattern: Egg Laying in Aplysia Cold Spring Harb Symp Quant Biol, January 1, 1983; 48(0): 405 - 412. [Abstract] [PDF]

				P Brownell and E Mayeri Prolonged inhibition of neurons by neuroendocrine cells in Aplysia Science, April 27, 1979; 204(4391): 417 - 420. [Abstract] [PDF]

				HAROLD. M. PINSKER and F. E. DUDEK Bag Cell Control of Egg Laying in Freely Behaving Aplysia Science, July 29, 1977; 197(4302): 490 - 493. [Abstract] [PDF]

				F. Dudek and J. Blankenship Neuroendocrine (bag) cells of Aplysia: spike blockade and a mechanism for potentiation Science, June 4, 1976; 192(4243): 1009 - 1010. [Abstract] [PDF]

Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents