Association of a Ras-related protein with cytochrome b of human neutrophils.
Activation of the superoxide generating system in human neutrophils is thought to involve the interaction or assembly of cytochrome b with other cytosolic and membrane proteins. We have now co-isolated by conventional purification procedures a protein of relative molecular mass 22,000 with cytochrome b. This Ras-related protein is not a fragment of either of the subunits of cytochrome b, and its primary structure, as determined by the sequencing of its complementary DNA, is identical to that predicted from a recently cloned ras-related gene, rap1 (also termed Krev-1). Immunoaffinity purification on anti-cytochrome and anti-Ras immunoaffinity matrices indicates an association between cytochrome b and the Ras-related protein. The association of a Ras-related GTP-binding protein with cytochrome b of human neutrophils could indicate a role for such a protein in the transduction, regulation or structure of the superoxide generating system.
Quinn
M T
MT
Department of Chemistry, Montana State University, Bozeman 59717.
Parkos
C A
CA
Walker
L
L
Orkin
S H
SH
Dinauer
M C
MC
Jesaitis
A J
AJ
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D003573:Cytochrome b Group / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009504:Neutrophils / Q000378:metabolism*; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D020668:rap GTP-Binding Proteins
D003573:Cytochrome b Group; D011518:Proto-Oncogene Proteins; D004247:DNA; D019204:GTP-Binding Proteins; D020668:rap GTP-Binding Proteins