Endocytosis by digest cells of the cattle tick Boophilus microplus: regulation by protein kinase C.
Endocytosis of fluorescently-labeled bovine serum albumin by digest cells of the gut of the cattle tick Boophilus microplus is inhibited by approx 60% in the presence of the tumour promoter 12-O-tetradecanoylphorbol 13-acetate. The results are consistent with a role for protein kinase C in regulating the uptake of blood meal by digest cells. Protein kinase C activity has been measured in the digest cell and the amount of enzyme has also been determined using a phorbol ester binding assay. The presence of a small number of specific protein kinase C substrates in the plasma membrane of the digest cell has been demonstrated. Preliminary experiments indicate that one of these substrates, a protein of approximately 30 kDa, is an integral membrane protein, part of which is exposed on the extracellular surface of the digest cell.
Liyou
N
N
Department of Biochemistry, University of Queensland, St Lucia, Australia.
Hamilton
S
S
Watters
D J
DJ
Tellam
R
R
Willadsen
P
P
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004064:Digestive System; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology; D005260:Female; D008969:Molecular Sequence Data; D011493:Protein Kinase C / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000378:metabolism / Q000494:pharmacology; D013987:Ticks / Q000378:metabolism*
D012710:Serum Albumin, Bovine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate