Nerve growth factor receptors: identification of distinct classes in plasma membranes and nuclei of embryonic dorsal root neurons.

Abstract

Two classes of receptors for '25I-labeled nerve growth factor in chick embryonic dorsal root neurons have been observed. One type is associated with the plasma membrane (or microsomal fraction) and can be completely solubilized by Triton X-100. These receptors display the nonsaturable binding isotherms and curvilinear Scatchard plots previously reported for nerve growth factor receptors in whole cells. The second class of binding sites is located in the nucleus, firmly bound to chromatin. These receptors are not solubilized by detergent, show saturable binding, and yield linear Scatchard plots of the type associated with a single class of binding sites of high affinity. The presence of the two receptor types suggests a bimodal mechanism of action for nerve growth factor. Nerve growth factor (NGF) is an insulin-like protein (1) that induces the morphologic and metabolic differentiation of sympathetic and sensory neurons in vertebrates (2). However, the responsiveness of these two tissues is quite different. Sensory neurons bind and are stimulated by NGF only during a relatively narrow period of embryonic development (2-4). In contrast, the sympathetic cells retain sensitivity, even in adult animals (5), although the nature of the response changes during different stages of development.The types of cellular processes effected by NGF are also variable. With low levels of hormone (about 1-10 ng), both sensory and sympathetic neurons produce the characteristic neurite outgrowth with accompanying general stimulation of anabolic metabolism and neurotubule polymerization (2, 6).At higher concentrations (about 1-10,tg), the specific induction of enzymes involved in nonadrenergic neurotransmitter synthesis is observed (7) as well as such effects as regeneration of adrenergic fibers in brain (8), inhibition of the biosynthesis of mucopolysaccharide in chrondrocytes (9), and stimulation of the temporal conversion of cell surface adhesive specificity in embryonic optic tectal cells (10).The responses associated with the low concentrations of NGF appear to be mediated through receptors bound to cell surface membranes. NGF covalently linked to Sepharose beads under conditions that prevent the release of soluble NGF produces a stimulation of neurite outgrowth from embryonic dorsal root sensory ganglia indistinguishable morphologically from that of the unbound hormone (11). By using 125I-labeled NGF (125I-NGF), these receptors have been shown to possess an affinity of approximately 1010 liters/mol (12-14), corresponding to the concentration range required for activity. However, the specific binding is a nonsaturable process with lower affinity (about 2 X 107 liters/mol) of binding sites at higher concentrations of labeled NGF (12). The range of affinities observed results from negatively cooperative interactions among a single class of receptor molecules, analogous to that observed for in- sulin receptors (15), rather than from receptor heterogeneity.Recently, it has also been demonstrated that NGF can be taken up by th...

Luteinizing hormone‐releasing hormone (LH‐RH) binding to purified rat pituitary nuclei

“…Since LH-RH stimulation of the anterior pituitary is known to increase the biosynthesis of gonadotrophic hormones [7] and the number of LH-RH receptors [8] it is possible that one of its sites of action is the nucleus. Internalisation and nuclear binding of peptide hormones has been demonstrated for insulin [9-l 11, EGF [12], NGF [13,14], LH [IS] and thyrotropin releasing hormone [ 161. Therefore, we have examined the binding of LH-RH and its analogues to purified anterior pituitary nuclei.…”

Polyoma virus middle T antigen: relationship to cell membranes and apparent lack of ATP-binding activity.

“…Receptors for certain hormones (e.g., insulin and nerve growth factor) have been reported to exist in both the nucleus and the plasma membrane (1,21,64). Nuclear receptors, in contrast to those of plasma membrane, are not extractable with nonionic detergents.…”

DNA synthesis-stimulating activities for BALB/3T3 cells present in histone and nonhistone protein fractions from rat rhodamine fibrosarcoma.

“…Furthermore, several examples of translocation of growth factors or hormones from the cytoplasm into the nucleus Abbreviations used: DSF, DNA synthesis factor; DME, Dulbecco's modified Eagle's medium PBS, phosphate-buffered saline; TCA, trichloroacetic acid; PMSF , phenylmethylsulfonylfluoride EDTA, ethylenediaminetetraacetate; SDS, sodium dodecylsulfate; FGF, fibroblast growth factor EGF, epidermal growth factor. have been reported (1,42,48). Moreover, growth factor-like activity has been shown to be present in histone and nonhistone protein fractions (2,20,30,46).…”