Priming-induced localization of G(ialpha2) in high density membrane microdomains.
Subcellular fractionation of human neutrophils on linear sucrose density gradients was utilized to test the hypothesis that priming regulates the subcellular and sub-plasma membrane distribution of neutrophil G-protein subunits, G(ialpha2) and G(ialpha3), N-formyl peptide receptor, Lyn kinase and phospholipase C(beta2). G(ialpha2), but not G(ialpha3), moved from a lighter to a higher density plasma membrane fraction. Unoccupied N-formyl peptide receptors were found throughout the plasma membrane fractions and this distribution did not change with priming. In unprimed cells G(ialpha2) and its effector, phospholipase C(beta2), were segregated in different membrane compartments; priming caused G(ialpha2) to move to the compartment in which phospholipase C(beta2) resided. Thus, an important component of the mechanism of priming may involve regulation of the location of G-proteins and effector molecules in plasma membrane compartments where their abilities to couple may be enhanced.
Keil
Michael L
ML
Department of Surgery, University of Michigan, Ann Arbor, MI 48105, USA.
Solomon
Naveenraj L
NL
Lodhi
Irfan J
IJ
Stone
Kimberley C
KC
Jesaitis
Algirdas J
AJ
Chang
Peter S
PS
Linderman
Jennifer J
JJ
Omann
Geneva M
GM
D000469:Alkaline Phosphatase / Q000378:metabolism; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism*; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D021962:Membrane Microdomains / Q000378:metabolism; D008954:Models, Biological; D019255:NADPH Oxidases / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D054799:Phospholipase C beta; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic / Q000378:metabolism; D018000:Receptors, Peptide / Q000378:metabolism; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D010738:Type C Phospholipases / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism
D007527:Isoenzymes; D008070:Lipopolysaccharides; D011518:Proto-Oncogene Proteins; D044042:Receptors, Formyl Peptide; D011971:Receptors, Immunologic; D018000:Receptors, Peptide; D014409:Tumor Necrosis Factor-alpha; D019255:NADPH Oxidases; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D000469:Alkaline Phosphatase; D010738:Type C Phospholipases; C518036:PLCB2 protein, human; D054799:Phospholipase C beta; C498819:GNAI3 protein, human; D051960:GTP-Binding Protein alpha Subunit, Gi2; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D020962:Heterotrimeric GTP-Binding Proteins