FUNPEP: Information system for "low complexity sequence regions".

Apolipoprotein A-I

Apolipoprotein A-I (apoA-I) is the major protein component of high density lipoproteins (HDL). ApoA-I has several functions:

structural properties of HDL;
cofactor for enzyme lechitin:colesterol acyltransferase (LCAT), which is essential for the reserve cholesterol transport;
interacting with membranes, which is requred for cholesterol efflux, hepatic uptake and interaction wit other lipoprotein particles.

Hereditary non-neuropathic systeic amyloidosis (Ostertag-type) is rare autosomal disease in which amyloid deposition in the viscera is usually fatal by the fifth decade. In some families it is caused by the mutations of apoA-I, but in other families lysozyme is the amyloid fibril protein. ApoA-I has four amyloidogenic variants:

Mutation	Exon	Fragment	Clinical symptoms
Gly26Arg	3	1-83	Neuropathy, nephropathy, peptic ulcer, low HDL, low apoA-I
Trp50Arg	4	1-86, 1-92, 1-93	Non-neuropathy amyloidosis, renal failure
Leu60Arg	4	1-88, 1-92, 1-93, 1-94	Non-neuropathy amyloidosis, renal failure
(60-71)ValThr	4	1-83, 1-92	Non-neuropathy amyloidosis, liver failure, low HDL, low apoA-I

Our SWISSPROT sequences are here, the result of the multiple sequence alignment is here.

Gergo Kiss 30th March 1999 EMBL/Szeged