TY - JOUR
T1 - Nuclear and cytoplasmic binding components for vitamin D metabolites
AU - Brumbaugh, Peter F.
AU - Haussler, Mark R.
N1 - Funding Information:
A similarity of the cytoplnemi.c and nuclear forms of the progesterone receptors in the oviduct tine been observed (16) . Thus, txo high nfPinity binding campone~e for 25-oHn3 wad 11z,2g-(OH) 2D3 ezist is the intestinal mucosa cytoeol xhich differ in their affiaitiee íbr the sterols . The components xhich are specific for 25~HU3 sediment nt 5-68 and are apparently not imrolved in the transport of sterol into the nucleus, xtiile the 1x,25-(OH)2D3 receptors sediment nt 3.79 and are readily detected in the aucleue follaring in vitro incúbation at temperatures of 25-370 " The possible relationship of these sterol binding components to the function of vitamin D in the stimulation of calcium twneport ie presentl yi under i~eetigation . Aoknonrledpcments -This research xas supported in part by USPA9 Gant AM15781, U9PHS Twining Gwat GM019ó2 and fonde fY"om the Ariaona Heart Association.
PY - 1975/2/1
Y1 - 1975/2/1
N2 - Specific binding of 1α,25-dihydroxyvitamin D3 to macromolecular components of small intestinal nuclei and cytosol is demonstrated. The nuclear 1α,25-dihydroxyvitamin D3 complex can be extracted from chromatin by 0.3 M KCl and sediments at 3.7S in sucrose density gradients. The cytoplasmic 1α,25-dihydroxyvitamin D3-binding components also sediment at 3.7S, identically to the nuclear complex under the ultracentrifugation procedures employed. Macromolecular binding components with a high affinity for 25-hydroxyvitamin D3 (Kd = 4.5 × 10-9 M) were also identified in intestinal cytosol which differ from the 1α,25-hydroxyvitamin D3 receptor in that: 1) they sediment at 5-6S in sucrose gradients, 2) they are observed in organs other than the intestine, and 3) while they do bind 1α,25-dihydroxyvitamin D3 at higher concentrations than 25-hydroxyvitamin D3, they are not observed to transfer either 25-hydroxyvitamin D3 or 1α,25-dihydroxyvitamin D3 to the nucleus, in vitro.
AB - Specific binding of 1α,25-dihydroxyvitamin D3 to macromolecular components of small intestinal nuclei and cytosol is demonstrated. The nuclear 1α,25-dihydroxyvitamin D3 complex can be extracted from chromatin by 0.3 M KCl and sediments at 3.7S in sucrose density gradients. The cytoplasmic 1α,25-dihydroxyvitamin D3-binding components also sediment at 3.7S, identically to the nuclear complex under the ultracentrifugation procedures employed. Macromolecular binding components with a high affinity for 25-hydroxyvitamin D3 (Kd = 4.5 × 10-9 M) were also identified in intestinal cytosol which differ from the 1α,25-hydroxyvitamin D3 receptor in that: 1) they sediment at 5-6S in sucrose gradients, 2) they are observed in organs other than the intestine, and 3) while they do bind 1α,25-dihydroxyvitamin D3 at higher concentrations than 25-hydroxyvitamin D3, they are not observed to transfer either 25-hydroxyvitamin D3 or 1α,25-dihydroxyvitamin D3 to the nucleus, in vitro.
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U2 - 10.1016/0024-3205(75)90256-8
DO - 10.1016/0024-3205(75)90256-8
M3 - Article
C2 - 165339
AN - SCOPUS:0016466246
SN - 0024-3205
VL - 16
SP - 353
EP - 362
JO - Life Sciences
JF - Life Sciences
IS - 3
ER -