Stimulation of a Cd-binding protein, and inhibition of the vitamin D-dependent calcium-binding protein, by zinc or cadmium in organ-cultured embryonic chick duodenum

Journal Article · Tue Jan 01 00:00:00 EST 1980 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(80)90254-4· OSTI ID:5841481

Corradino, R A; Fullmer, C S

Embryonic chick duodenum maintained in organ culture responds to 1 ..cap alpha..,25-dihydroxy vitamin D/sub 3/ in the culture medium by de novo synthesis of a specific calcium-binding protein (CaBP). The addition of Cd/sup 2 +/(3-5 x 10/sup -5/ M) or Zn/sup 2 +/(10/sup -5/-10/sup -4/ M) to the medium inhibited CaBP, but stimulated biosynthesis of a Cd-binding protein (CdBP). CdBP in duodenal homogenate supernatants was assessed in two ways: first, by its /sup 109/Cd-binding activity (/sup 109/CdBA) using a competitive ion exchange procedure; and, second, by the extent of (/sup 35/S)-cystine incorporation into a specific peak or band after gel filtration or analytical polyacrylamide disc gel electrophoresis, respectively. Regardless of whether cadmium- or zinc-stimulated, the /sup 35/S-labeled CdBP - the only protein significantly labeled under the conditions employed - migrated identically upon gel filtration and electrophoresis, and comigrated with purified chick liver Cd-metallothionein. Neither actinomycin D nor ..cap alpha..-amanitin, in concentrations sufficient to severely inhibit CaBP, significantly reduced CdBP production. However, cycloheximide did inhibit either Cd/sup 2 +/- or Zn/sup 2 +/-stimulated CdBP by about 50% at an inhibitor concentration which abolished CaBP. The inhibitor studies, coupled with the observations of extensive incorporation of (/sup 35/S)cystine into CdBP, suggest that the metals stimulated biosynthesis by a mechanism operating at the translational level. The organ-cultured duodenum seems well suited for studies of the regulation of CdBP biosynthesis especially since it responds predictably to the steroid hormone, 1..cap alpha..,25-dihydroxy vitamin D/sub 3/, in the induction of another specific protein, CaBP, at the transcriptional level. The biosynthesis of CaBP thus may serve as a convenient control in studies of CdBP production under various experimental conditions.

• Research Organization: Cornell Univ., Ithaca, NY
• DOE Contract Number: EY-76-S-02-2792
• OSTI ID: 5841481
• Journal Information: Arch. Biochem. Biophys.; (United States), Vol. 199:1
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
CADMIUM
BIOLOGICAL EFFECTS
EMBRYONIC CELLS
SENSITIVITY
ZINC
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
CADMIUM 109
CPB
CYSTINE
LABELLED COMPOUNDS
SMALL INTESTINE
SULFUR 35
TISSUE CULTURES
VITAMIN D
AMINO ACIDS
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CADMIUM ISOTOPES
CARBOXYLIC ACIDS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISULFIDES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
GASTROINTESTINAL TRACT
INTERMEDIATE MASS NUCLEI
INTESTINES
ISOTOPES
KINETICS
LIGHT NUCLEI
METALS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
RADIOISOTOPES
REACTION KINETICS
SULFUR ISOTOPES
SYNTHESIS
VITAMINS
YEARS LIVING RADIOISOTOPES
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