Title
Analysis by mass spectrometry of POMC-derived peptides in amphibian melanotrope subpopulations
Author
Vázquez-Martínez, R.M.
Malagón, M.M.
van Strien, F.J.C.
Jespersen, S.
van der Greef, J.
Roubos, E.W.
Gracia-Navarro, F.
Centraal Instituut voor Voedingsonderzoek TNO
Publication year
1999
Abstract
We have previously shown that the melanotrope population of the pituitary intermediate lobe of Rana ridibunda is composed of two subpopulations, of low (LD) and high density (HD), that show distinct ultrastructural features and display different synthetic and secretory rates. To investigate whether LD and HD melanotrope cells also differ in proopiomelanocortin (POMC) processing, we have analyzed the POMC-end products in single cells from both subpopulations by means of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The mass spectra revealed the presence of 8 POMC-derived peptides in HD and LD melanotrope cells, indicating a similar processing of the precursor in both subpopulations. However, the relative abundance of three POMC-end products (i.e. lys-γ1- MSH, acetyl-α-MSH, and CLIP fragment) was higher in the HD subset. Moreover, two peptides with molecular weights of 1030 and 1818 Da, respectively, were detected that could not be assigned to any product deduced from the frog POMC sequence. The relative amount of the 1030 Da peptide was higher in LD melanotrope cells. Taken together, our results suggest that POMC processing is differentially regulated in the two melanotrope cell subsets.
Subject
Nutrition
Cell heterogeneity
MALDI-MS
Melanotrope cells
POMC
Rana ridibunda
Beta endorphin
Beta intermedin
Corticotropin[18-39]
Proopiomelanocortin
Protein precursor
Cell density
Cell heterogeneity
Cell subpopulation
Frog
Hypophysis intermediate lobe
Mass spectrometry
Nonhuman
Protein analysis
Protein expression
Protein processing
Protein secretion
Regulatory mechanism
Animals
Male
Mass Spectrometry
Pituitary Gland
Pro-Opiomelanocortin
Radioimmunoassay
Rana ridibunda
Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
Amphibia
Anura
Rana ridibunda
To reference this document use:
http://resolver.tudelft.nl/uuid:633a999a-835c-4eb0-be3b-6582c1b036bb
DOI
https://doi.org/10.1016/s0024-3205(99)00018-1
TNO identifier
234938
ISSN
0024-3205
Source
Life Sciences, 64 (11), 923-930
Document type
article