An analysis of the proopiomelanocortin systems in the pituitary of the squamate reptile Lacerta galloti.
Acid extracts of the pars intermedia of the squamate reptile Lacerta galloti were screened for immunoreactive forms of proopiomelanocortin (POMC)-related end products following Sephadex G-50 column chromatography. alpha-MSH-sized end products were detected with a Val-NH2, C-terminal-specific RIA, and beta-endorphin-sized end products were detected with a separate C-terminal-directed RIA. Five peaks of alpha-MSH-related immunoreactivity were isolated following fractionation by reversed-phase HPLC. Based on a comparison of the reversed-phase HPLC properties and the net positive charges (pH 2.75) of the Lacerta forms of alpha-MSH to those of the mammalian forms of alpha-MSH and Anolis carolinensis ACTH(1-13)NH2, it appears that the N-acetylation of alpha-MSH is a major post-translational processing event in the pars intermedia of L. galloti. Although multiple forms of beta-endorphin were detected in the pars intermedia of L. galloti following cation-exchange chromatography, the low levels of N-acetylated beta-endorphin detected with an N-acetyl-specific beta-endorphin RIA indicate that the N-acetylation of beta-endorphin in this species is a minor post-translational processing event. This pattern of POMC processing in the pars intermedia of L. galloti is similar to the processing events observed for the turtle Pseudemys scripta, but distinct from the processing events observed in the squamate reptile A. carolinensis.
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Departamento de Microbiologia y Biologia Celular, Universidad de La Laguna, Canary Islands, Spain.
Batista
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Dores
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D000107:Acetylation; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005260:Female; D008116:Lizards / Q000378:metabolism*; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism*; D011333:Pro-Opiomelanocortin / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D000521:alpha-MSH / Q000032:analysis / Q000378:metabolism; D001615:beta-Endorphin / Q000032:analysis / Q000378:metabolism
D000521:alpha-MSH; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin