Insulin receptor: insulin-modulated interconversion between distinct molecular forms involving disulfide sulfhydryl exchange

Maturo, Joseph M.; Hollenberg, Morley D.; Aglio, Linda S.

doi:10.1021/bi00279a040

Cited by 44 publications

(24 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is not clear from their data that the peak ofautophosphorylation activity correlated to the presence of a2f32 or appearance of af3. Whether the (af3) form exists as such, or in noncovalently associated form such as (a/3)(afl), has not been determined in our system, although other investigators have observed free af3 in dithiothreitol-treated solubilized receptors fractionated by sucrose density gradient sedimentation and/or gel filtration on Sepharose 6B (24)(25)(26). Our result that one-half of the intact receptor shows a higher insulin-dependent kinase activity is intriguing.…”

Section: Discussionmentioning

confidence: 66%

The monomeric alpha beta form of the insulin receptor exhibits much higher insulin-dependent tyrosine-specific protein kinase activity than the intact alpha 2 beta 2 form of the receptor.

Fujita‐Yamaguchi¹,

Kathuria²

1985

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The relationship between the structure of the insulin receptor and its kinase activity was studied on the purified receptor treated with different concentrations of dithiothreitol. An enhanced autophosphorylation of the 13 subunit (Mr, 90,000) was observed on NaDodSO4/PAGE under reducing conditions when the receptor was treated with 0.1-0.75 mM dithiothreitol in the presence of 1 ,LM insulin. Since we have previously observed (unpublished data) that incubation of the purified receptor with 1 mM dithiothreitol completely reduced an intact form of the receptor, a2132, to free a subunit (Mr, 125,000) and .8 subunit, the population of disulfide-linked complexes of the receptor after the dithiothreitol treatment was analyzed by NaDodSO4/PAGE under nonreducing conditions. The same receptor preparations were assayed for tyrosine kinase activity by using an exogenous substrate. Treatment of the receptor with dithiothreitol significantly enhanced both basal and insulin-dependent kinase activity. The kinase activity was enhanced 12-to 37-fold at concentrations of 0.5-0.75 mM dithiothreitol in the presence of 1 1AM insulin. The amount of a2132, as3, and /8 forms in each dithiothreitol-treated receptor preparation was quantified and compared with its kinase activity. These studies clearly indicate a correlation between the appearance of an aj8 form and an increase in kinase activity. Therefore, we conclude that the afi form of the insulin receptor exhibits much higher kinase activity than the intact receptor in the a2P2 form.

show abstract

Section: Discussionmentioning

confidence: 66%

The monomeric alpha beta form of the insulin receptor exhibits much higher insulin-dependent tyrosine-specific protein kinase activity than the intact alpha 2 beta 2 form of the receptor.

Fujita‐Yamaguchi¹,

Kathuria²

1985

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…An insulin-induced interchange between two receptor forms of 7.0 nm and about 4.0 nm has been reported by Ginsberg et al [43] and Maturo et al [46]. More recently Maturo and Hollenberg [50] suggest that the larger receptor complex mainly reveals an stoichiometry while the smaller one consists of ctfl receptor species.…”

Section: Discussionmentioning

confidence: 67%

Structural requirements for signal transduction of the insulin receptor

Florke¹,

Klein²,

Reinauer³

1990

European Journal of Biochemistry

View full text Add to dashboard Cite

Structural requirements for signal processing by human placental insulin receptors have been examined. Insulin binding has been found to change the physico-chemical properties of (~8 )~ receptors solubilized with Triton X-100, indicating a marked alteration of the form, i.e. size and shape, of the molecular complex. (a) The Stokes radius decreases from about 9.5 nm to 7.9 nm, as determined by PAGE with Triton X-100 in the buffer (Triton X-lOO/PAGE), and from 9.1 nm to 8.7 nm, as assessed by gel filtration. (b) The sedimentation coefficient s20,w rises from 10.1 S to 11.4 S. Upon dissociation of the receptor-hormone complex, the alterations are reversed. After autophosphorylation of hormone-bound (ap)2-insulin receptors, phosphate incorporation was found for 7.9-nm receptor forms when receptor-insulin complexes were crosslinked with disuccinimide suberate prior to Triton X-lOO/PAGE. However, phosphate incorporation was demonstrated for the 9.5-nm receptor forms when receptorinsulin complexes were not prevented from dissociation. This strongly indicates that the (EB)~ receptor is autophosphorylated after assuming its 7.9-nm form upon insulin binding. Moreover, the insulin-dependent structural alterations are not affected by autophosphorylation.In contrast to (ap)2 receptors, the diffusion and the sedimentation behaviour of up receptors, which carry a dormant tyrosine kinase even in the hormone-laden state, has been found to be insensitive to insulin binding. Different molecular properties of a8 and ( C I~)~ receptors have also been detected by hormone binding studies.Insulin binding to ( E P )~ and a8 receptors differs markedly with respect to pH, ionic strength, and temperature.This might indicate that the structure of the hormone binding domain of up receptor changes on association into the ( C I~)~ species. Alternatively, distinct hormone-induced conformational alterations at the molecular level of a/3 and Our data demonstrate that the (afl)2-insulin receptor undergoes extended conformational alterations upon insulin binding. This capacity for structural changes coincides with the hormone-inducable enhancement of tyrosine autophosphorylation of the 7.9-nm insulin-bound receptor form. In contrast, ap receptors appear to be locked in an inactive nonconvertable state. Thus, interaction between two aP receptor units is required to allow extended conformational alterations. which are assumed to be the triggering event for augmented autophosphorylation.receptor species may lead to the different binding properties.

show abstract

“…Since these early studies, the role($ of thiol groups in the plant growth process have received little additional attention, except in the report by Spring et al (1988), where NEM was suggested i o inhibit growth by reacting with thiol groups unmasked by auxin treatment. Reported possibilities for involvements of thiols in the action of mammalian hormones at the plasma membrane include interactions with insulin (Maturo et al, 1983), muscarinic (Aronstam et al, 19781, dopamine (Suen et al, 1980;Sidhu et al, 1986), opiate (Larsen et al, 19811, P-adrenergic (Bottari et al, 1979), vasopressin (F'avo andFarenholz, 1990), leukotirene 84 (Falcone and rlharony, 1990), and peptide (E1 Battari et al, 1988) receptors.…”

Section: Discussionmentioning

confidence: 99%

Selective Inhibition of Auxin-Stimulated NADH Oxidase Activity and Elongation Growth of Soybean Hypocotyls by Thiol Reagents

et al. 1995

View full text Add to dashboard Cite

l h e NADH oxidase activity of isolated vesicles of soybean (Glycine max cv Williams 82) plasma membranes and elongation growth of 1 -cm-long hypocotyl segments were stimulated by auxins (indole-3-acetic acid or 2,4-dichlorophenoxyacetic acid [2,4-D1). l h e auxin-induced stimulations of both NADH oxidase and growth were prevented by the thiol reagents N-ethylmaleimide, pchloromercuribenzoate, 5,5'-dithiobis(2-nitrophenylbenzoic acid), dithiothreitol, and reduced glutathione. These same reagents largely were without effect on or stimulated slightly the basal levels of NADH oxidase and growth when assayed in the absence of auxins. In the presence of dithiothreitol or reduced glutathione, both 2,4-D and indole-3-acetic acid either failed to stimulate or inhibited the NADH oxidase activity. l h e rapidity of the response at a given concentration of thiol reagent and the degree of inhibition of the 2,4-D-induced NADH oxidase activity were dependent on order of reagent addition. I f the thiol reagents were added first, auxin stimulations were prevented. I f auxins were added first, the inhibitions by the thiol reagents were delayed or higher concentrations of thiol reagents were required to achieve inhibition. The results demonstrate a fundamental difference between the auxin-stimulated and the constitutive NADH oxidase activities of soybean plasma membranes that suggest an involvement of active-site thiols in the auxinstimulated but not in the constitutive activity. Morré et al. (1986) observed that the oxidation of NADH by isolated soybean (Glycine mux) plasma membranes was stimulated by 2,4-D. This stimulation did not require addition of exogenous electron acceptors such as ascorbate radical or hexacyanoferrate 111, and electron transfer presumably was either to oxygen or endogenous electron acceptors associated with the plasma membrane (Morre and Brightman, 1991). That this stimulation was distinct from that of the oxygen burst NAD(P)H oxidase of host defense was indicated by the observation that oxidation of NADPH was not stimulated by auxin (Morre and Brightman, 1991).The auxin-stimulated NADH oxidase activity was purified from soybean plasma membrane by Brightman et al. (1988) as a complex of three proteins with molecular masses of 36, 55, and 72 kD. The NADH oxidase activity and the plasma membrane NADH:hexacyanoferrate I11 oxidoreductase did not co-purify and appeared to reside on different proteins (Morré and Brightman, 1991 The present report demonstrates that the auxin-stimulated component of the NADH oxidase is inhibited by thiol reagents. The auxin-induced elongation growth of hypocotyl segments is inhibited specifically by these same thiol reagents. The findings provide evidence for a fundamental difference between the auxin-induced and the constitutive NADH oxidase activities of plasma membrane vesicles from soybean hypocotyls that also is observed for auxininduced cell elongation. The difference appears to derive from an involvement of thiols at the active site in the auxin-stimulated but not in th...

show abstract

Insulin receptor: insulin-modulated interconversion between distinct molecular forms involving disulfide sulfhydryl exchange

Cited by 44 publications

References 28 publications

The monomeric alpha beta form of the insulin receptor exhibits much higher insulin-dependent tyrosine-specific protein kinase activity than the intact alpha 2 beta 2 form of the receptor.

The monomeric alpha beta form of the insulin receptor exhibits much higher insulin-dependent tyrosine-specific protein kinase activity than the intact alpha 2 beta 2 form of the receptor.

Structural requirements for signal transduction of the insulin receptor

Selective Inhibition of Auxin-Stimulated NADH Oxidase Activity and Elongation Growth of Soybean Hypocotyls by Thiol Reagents

Contact Info

Product

Resources

About