Association and colocalization of G protein alpha subunits and Purkinje cell protein 2 (Pcp2) in mammalian cerebellum.
Previously, we have demonstrated a novel interaction between Galpha(o) protein and Purkinje cell protein-2 (Pcp2, also known as L7) in vitro and in transfected cells (Luo and Denker [1999] J. Biol. Chem. 274:10685-10688). Pcp2 is uniquely expressed in cerebellar Purkinje cells and in retinal bipolar neurons, and it may function as a cell-type specific modulator for G protein-mediated cell signaling. This interaction has been further evaluated in the present studies. Coimmunoprecipitation experiments reveal that Pcp2 associates with Galpha(o) in vivo in mouse cerebellum and eye extract. Pcp2 also associate with Galpha(i2) in the cerebellum. No detectable associations of Pcp2 with Galpha(z) and Galpha(q) subunits are observed. The association of Galpha(o) and Pcp2 is detected at postnatal day 1 (P1), and the association remains stable from day 3 (P3) until adulthood. Further, immunofluorescent double labeling and confocal microscopy suggest that Pcp2 and Galpha(o) are colocalized in the distal processes of cerebellar Purkinje cells including axonal endings and dendritic spines. Taken together, these findings indicate colocalization and association of Galpha(o) and Pcp2 in cerebellum and suggest a functional role in regions of synaptic activity.
Redd
Kacy J
KJ
Department of Biological Sciences, University of Southern Mississippi, 2609 W. 4th Street, Hattiesburg, MS 39406-5018, USA.
Oberdick
John
J
McCoy
John
J
Denker
Bradley M
BM
Luo
Yuan
Y
D000367:Age Factors; D000818:Animals; D005123:Eye / Q000737:chemistry / Q000378:metabolism; D051960:GTP-Binding Protein alpha Subunit, Gi2; D044385:GTP-Binding Protein alpha Subunits; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000032:analysis / Q000378:metabolism*; D020962:Heterotrimeric GTP-Binding Proteins / Q000032:analysis / Q000378:metabolism; D008322:Mammals; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000032:analysis / Q000378:metabolism*; D011689:Purkinje Cells / Q000737:chemistry / Q000378:metabolism*
D044385:GTP-Binding Protein alpha Subunits; D009419:Nerve Tissue Proteins; D011518:Proto-Oncogene Proteins; C091104:Purkinje cell protein L7; C084618:olfactory G protein subunit alpha olf; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; C498016:Gnai2 protein, mouse; D020962:Heterotrimeric GTP-Binding Proteins