Xenopus oocytes express multiple receptors for lpa-like lipid
mediators.
Liliom, Kroly, Kimiko Murakami-Murofushi, Susumu Kobayashi, Hiromu
Murofushi, Gabor Tigyi.
Department of Physiology and Biophysics, University of Tennessee
Memphis; Department of Biology, Faculty of Science, Ochanomizu
University, Tokyo; Sagami Chemical Research Center, Nishiohnuma, and
#Department of Biochemistry and Biophysics, University of Tokyo,
Tokyo
APStracts 2:0342C, 1995.
In Xenopus oocytes, lysophosphatidic acid (LPA) and a cyclic
phosphate-containing analog, 1-acyl-sn-glycero-2,3-cyclic phosphate
(cLPA) isolated from Physarum, both activate oscillatory Cl-
currents. cLPA elicited oscillatory currents only when applied
extracellularly and similarly to LPA evoked homologous
desensitization. cLPA applied to oocytes previously desensitized by
LPA failed to elicit a current, indicating that LPA completely
desensitized the cLPA receptors. In contrast, when oocytes were
desensitized by cLPA, LPA still evoked large currents. The lack of
heterologous desensitization between cLPA and LPA indicates that the
former acts on a distinct receptor subpopulation(s), which is also
activated by LPA. The alkyl-ether analog 1-hexadecyl-2-lyso-sn
-glycero-3-phosphate (16:0-GP) and dioleoyl-phosphatidic acid (18:1
-PA) showed heterologous desensitization patterns similar to that of
LPA with regard to cLPA. Complete heterologous desensitization was
obtained between LPA and 16:0-GP or 18:1-PA. These observations
demonstrate the simultaneous expression of at least two different
types of receptors for LPA-like lipid mediators on Xenopus oocytes,
and that these receptors show different pharmacological properties in
their selectivity to cLPA.
Received 14 August 1995; accepted in final form 11 September
1995.
APS Manuscript Number C506-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 31 October 95