The adipsin-acylation stimulating protein system and regulation of intracellular triglyceride synthesis.
We have previously characterized an activity from human plasma that markedly stimulates triglyceride synthesis in cultured human skin fibroblasts and human adipocytes. Based on its in vitro activity we named the active component acylation stimulating protein (ASP). The molecular identity of the active serum component has now been determined. NH2-terminal sequence analysis, ion spray ionization mass spectroscopy, and amino acid composition analysis all indicate that the active purified protein is a fragment of the third component of plasma complement, C3a-desArg. As well, reconstitution experiments with complement factors B, D, and complement C3, the components necessary to generate C3a, have confirmed the identity of ASP as C3a. ASP appears to be the final effector molecule generated by a novel regulatory system that modulates the rate of triglyceride synthesis in adipocytes.
McGill Unit for the Prevention of Cardiovascular Disease, Royal Victoria Hospital, Montreal, Quebec, Canada.
A
A
Baldo
A D
AD
Sniderman
S
S
St-Luce
R K
RK
Avramoglu
M
M
Maslowska
B
B
Hoang
J C
JC
Monge
A
A
Bell
S
S
Mulay
K
K
Cianflone
D000595:Amino Acid Sequence; D015926:Complement C3a / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D011416:Complement Factor D; D006801:Humans; D008969:Molecular Sequence Data; D012697:Serine Endopeptidases / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism*
D014280:Triglycerides; C044541:complement C3a, des-Arg-(77)-; D015926:Complement C3a; D012697:Serine Endopeptidases; C493488:CFD protein, human; D011416:Complement Factor D