title: High density and ligand affinity confer ultrasensitive signal detection by a guanylyl cyclase chemoreceptor.
abstract: Guanylyl cyclases (GCs), which synthesize the messenger cyclic guanosine 3',5'-monophosphate, control several sensory functions, such as phototransduction, chemosensation, and thermosensation, in many species from worms to mammals. The GC chemoreceptor in sea urchin sperm can decode chemoattractant concentrations with single-molecule sensitivity. The molecular and cellular underpinnings of such ultrasensitivity are not known for any eukaryotic chemoreceptor. In this paper, we show that an exquisitely high density of 3 × 10(5) GC chemoreceptors and subnanomolar ligand affinity provide a high ligand-capture efficacy and render sperm perfect absorbers. The GC activity is terminated within 150 ms by dephosphorylation steps of the receptor, which provides a means for precise control of the GC lifetime and which reduces "molecule noise." Compared with other ultrasensitive sensory systems, the 10-fold signal amplification by the GC receptor is surprisingly low. The hallmarks of this signaling mechanism provide a blueprint for chemical sensing in small compartments, such as olfactory cilia, insect antennae, or even synaptic boutons.
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany Marine Biological Laboratory, Woods Hole, MA 02543.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Pichlo
authors.affiliation: Marine Biological Laboratory, Woods Hole, MA 02543 Institute of Complex Systems (ICS-4), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Bungert-Plümke
authors.affiliation: Marine Biological Laboratory, Woods Hole, MA 02543 Institute of Complex Systems (ICS-4), Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Weyand
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany Marine Biological Laboratory, Woods Hole, MA 02543.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Seifert
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bönigk
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany Marine Biological Laboratory, Woods Hole, MA 02543.
authors.forename: Timo
authors.initials: T
authors.lastname: Strünker
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany Marine Biological Laboratory, Woods Hole, MA 02543 Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton BN1 9QG, England, UK.
authors.forename: Nachiket Dilip
authors.initials: ND
authors.lastname: Kashikar
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany Marine Biological Laboratory, Woods Hole, MA 02543 Babraham Institute, Cambridge CB22 3AT, England, UK.
authors.forename: Normann
authors.initials: N
authors.lastname: Goodwin
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Müller
authors.affiliation: Marine Biological Laboratory, Woods Hole, MA 02543 Department of Functional Neuroanatomy, Institute of Anatomy and Cell Biology, Heidelberg University, 69120 Heidelberg, Germany.
authors.forename: Patric
authors.initials: P
authors.lastname: Pelzer
authors.affiliation: III. Physikalisches Institut, Universität Göttingen, 37077 Göttingen, Germany.
authors.forename: Qui
authors.initials: Q
authors.lastname: Van
authors.affiliation: III. Physikalisches Institut, Universität Göttingen, 37077 Göttingen, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Enderlein
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany.
authors.forename: Clementine
authors.initials: C
authors.lastname: Klemm
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, 13125 Berlin, Germany.
authors.forename: Eberhard
authors.initials: E
authors.lastname: Krause
authors.affiliation: Plant Biochemistry, Ruhr University Bochum. 44801 Bochum, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Trötschel
authors.affiliation: Plant Biochemistry, Ruhr University Bochum. 44801 Bochum, Germany.
authors.forename: Ansgar
authors.initials: A
authors.lastname: Poetsch
authors.affiliation: Institut für Molekulare Immunologie, Helmholtz-Zentrum München, 81377 München, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Kremmer
authors.affiliation: Center of Advanced European Studies and Research, 53175 Bonn, Germany Marine Biological Laboratory, Woods Hole, MA 02543 u.b.kaupp@caesar.de.
authors.forename: U Benjamin
authors.initials: UB
authors.lastname: Kaupp
authors.forename: Heinz G
authors.initials: HG
authors.lastname: Körschen
authors.forename: Ursel
authors.initials: U
authors.lastname: Collienne
mesh_terms: D000818:Animals; D047308:Arbacia / Q000378:metabolism*; D002628:Chemoreceptor Cells / Q000378:metabolism; D002630:Chemotactic Factors / Q000502:physiology; D006152:Cyclic GMP / Q000096:biosynthesis*; D006162:Guanylate Cyclase / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D010766:Phosphorylation; D011485:Protein Binding; D050705:Receptors, Guanylate Cyclase-Coupled / Q000378:metabolism*; D015398:Signal Transduction; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D002630:Chemotactic Factors; D006162:Guanylate Cyclase; D050705:Receptors, Guanylate Cyclase-Coupled; D006152:Cyclic GMP