Ligand-induced modification of a surface cAMP receptor of Dictyostelium discoideum does not require its occupancy

B. E. Snaar-Jagalska, Peter N Devreotes, P. J M Van Haastert

Research output: Contribution to journalArticle

Abstract

In Dictyostelium discoideum amoebae, cAMP-induced phosphorylation of the surface cAMP receptor is associated with a discrete transition in its electrophoretic mobility. The native and modified forms of the receptor are designated R and D (M(r) = 40,000 and 43,000). The relationship of the number of receptors which are modified as a function of the receptors which bind cAMP was investigated. Modification was assessed by determining the amounts of R and D forms in Western blots which detect all receptors whether or not they are exposed on the surface. Cyclic AMP or the analog, adenosine 3',5'-monophosphorothioate ((R(p))-cAMPS), induced a loss of cAMP-binding activity (down-regulation), which was not accompanied by a loss of the receptor protein. About 60% of the receptors do not bind cAMP in the absence of Ca2+ and are unmasked by 10 mM Ca2+. However, the fraction of receptors which are modified in response to cAMP is equal in the absence or presence of Ca2+. (R(p))-cAMPS induces down-regulation (50%) but not modification. Addition of cAMP, following down-regulation by (R(p))-cAMPS, causes all receptors to be modified. cAMP-induces both down-regulation (80%) and modification. Modification is more readily reversed than down-regulation: 30 min after removal of cAMP, receptors remain down-regulated (57%) but are found in the R form. All receptors shift to the D form when cAMP is readded to the cells. These results indicate that exposed, as well as cryptic and down-regulated receptors, are modified in response to the cAMP stimulus.

Original languageEnglish (US)
Pages (from-to)897-901
Number of pages5
JournalJournal of Biological Chemistry
Volume263
Issue number2
StatePublished - 1988
Externally publishedYes

Fingerprint

Cyclic AMP Receptors
Dictyostelium
Down-Regulation
Ligands
Electrophoretic mobility
Phosphorylation
Amoeba
Cyclic AMP
Western Blotting
adenosine-3',5'-cyclic phosphorothioate
Proteins

ASJC Scopus subject areas

  • Biochemistry

Cite this

Ligand-induced modification of a surface cAMP receptor of Dictyostelium discoideum does not require its occupancy. / Snaar-Jagalska, B. E.; Devreotes, Peter N; Van Haastert, P. J M.

In: Journal of Biological Chemistry, Vol. 263, No. 2, 1988, p. 897-901.

Research output: Contribution to journalArticle

@article{59f6c92eaad14116a22480fc7ce6aca4,
title = "Ligand-induced modification of a surface cAMP receptor of Dictyostelium discoideum does not require its occupancy",
abstract = "In Dictyostelium discoideum amoebae, cAMP-induced phosphorylation of the surface cAMP receptor is associated with a discrete transition in its electrophoretic mobility. The native and modified forms of the receptor are designated R and D (M(r) = 40,000 and 43,000). The relationship of the number of receptors which are modified as a function of the receptors which bind cAMP was investigated. Modification was assessed by determining the amounts of R and D forms in Western blots which detect all receptors whether or not they are exposed on the surface. Cyclic AMP or the analog, adenosine 3',5'-monophosphorothioate ((R(p))-cAMPS), induced a loss of cAMP-binding activity (down-regulation), which was not accompanied by a loss of the receptor protein. About 60{\%} of the receptors do not bind cAMP in the absence of Ca2+ and are unmasked by 10 mM Ca2+. However, the fraction of receptors which are modified in response to cAMP is equal in the absence or presence of Ca2+. (R(p))-cAMPS induces down-regulation (50{\%}) but not modification. Addition of cAMP, following down-regulation by (R(p))-cAMPS, causes all receptors to be modified. cAMP-induces both down-regulation (80{\%}) and modification. Modification is more readily reversed than down-regulation: 30 min after removal of cAMP, receptors remain down-regulated (57{\%}) but are found in the R form. All receptors shift to the D form when cAMP is readded to the cells. These results indicate that exposed, as well as cryptic and down-regulated receptors, are modified in response to the cAMP stimulus.",
author = "Snaar-Jagalska, {B. E.} and Devreotes, {Peter N} and {Van Haastert}, {P. J M}",
year = "1988",
language = "English (US)",
volume = "263",
pages = "897--901",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "2",

}

TY - JOUR

T1 - Ligand-induced modification of a surface cAMP receptor of Dictyostelium discoideum does not require its occupancy

AU - Snaar-Jagalska, B. E.

AU - Devreotes, Peter N

AU - Van Haastert, P. J M

PY - 1988

Y1 - 1988

N2 - In Dictyostelium discoideum amoebae, cAMP-induced phosphorylation of the surface cAMP receptor is associated with a discrete transition in its electrophoretic mobility. The native and modified forms of the receptor are designated R and D (M(r) = 40,000 and 43,000). The relationship of the number of receptors which are modified as a function of the receptors which bind cAMP was investigated. Modification was assessed by determining the amounts of R and D forms in Western blots which detect all receptors whether or not they are exposed on the surface. Cyclic AMP or the analog, adenosine 3',5'-monophosphorothioate ((R(p))-cAMPS), induced a loss of cAMP-binding activity (down-regulation), which was not accompanied by a loss of the receptor protein. About 60% of the receptors do not bind cAMP in the absence of Ca2+ and are unmasked by 10 mM Ca2+. However, the fraction of receptors which are modified in response to cAMP is equal in the absence or presence of Ca2+. (R(p))-cAMPS induces down-regulation (50%) but not modification. Addition of cAMP, following down-regulation by (R(p))-cAMPS, causes all receptors to be modified. cAMP-induces both down-regulation (80%) and modification. Modification is more readily reversed than down-regulation: 30 min after removal of cAMP, receptors remain down-regulated (57%) but are found in the R form. All receptors shift to the D form when cAMP is readded to the cells. These results indicate that exposed, as well as cryptic and down-regulated receptors, are modified in response to the cAMP stimulus.

AB - In Dictyostelium discoideum amoebae, cAMP-induced phosphorylation of the surface cAMP receptor is associated with a discrete transition in its electrophoretic mobility. The native and modified forms of the receptor are designated R and D (M(r) = 40,000 and 43,000). The relationship of the number of receptors which are modified as a function of the receptors which bind cAMP was investigated. Modification was assessed by determining the amounts of R and D forms in Western blots which detect all receptors whether or not they are exposed on the surface. Cyclic AMP or the analog, adenosine 3',5'-monophosphorothioate ((R(p))-cAMPS), induced a loss of cAMP-binding activity (down-regulation), which was not accompanied by a loss of the receptor protein. About 60% of the receptors do not bind cAMP in the absence of Ca2+ and are unmasked by 10 mM Ca2+. However, the fraction of receptors which are modified in response to cAMP is equal in the absence or presence of Ca2+. (R(p))-cAMPS induces down-regulation (50%) but not modification. Addition of cAMP, following down-regulation by (R(p))-cAMPS, causes all receptors to be modified. cAMP-induces both down-regulation (80%) and modification. Modification is more readily reversed than down-regulation: 30 min after removal of cAMP, receptors remain down-regulated (57%) but are found in the R form. All receptors shift to the D form when cAMP is readded to the cells. These results indicate that exposed, as well as cryptic and down-regulated receptors, are modified in response to the cAMP stimulus.

UR - http://www.scopus.com/inward/record.url?scp=0023829591&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023829591&partnerID=8YFLogxK

M3 - Article

C2 - 2826466

AN - SCOPUS:0023829591

VL - 263

SP - 897

EP - 901

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 2

ER -