Vol. 279, Issue 1, C205-C212, July 2000
Cloning of murine glycosyl phosphatidylinositol anchor
attachment protein, GPAA1
Y.
Hiroi1,
R.
Chen2,
H.
Sawa3,
T.
Hosoda1,
S.
Kudoh1,
Y.
Kobayashi3,
H.
Aburatani1,
K.
Nagashima3,
R.
Nagai1,
Y.
Yazaki1,
M. E.
Medof2, and
I.
Komuro1
1 Department of Cardiovascular Medicine, University of
Tokyo Graduate School of Medicine, Tokyo 113-8655; and
3 Department of Pathology, University of Hokkaido School of
Medicine, Sapporo, Japan; and 2 Institute of Pathology, Case
Western Reserve University, Cleveland, Ohio
Glycosyl phosphatidylinositols (GPIs) are used
to anchor many proteins to the cell surface membrane and are utilized
in all eukaryotic cells. GPI anchoring units are attached to proteins via a transamidase reaction mediated by a GPI transamidase complex. We
isolated one of the components of this complex,
mGPAA1 (murine GPI anchor attachment), by the signal
sequence trap method. mGPAA1 cDNA is about 2 kb in length
and encodes a putative 621 amino acid protein. The mGPAA1
gene has 12 small exons and 11 small introns. mGPAA1 mRNA is
ubiquitously expressed in mammalian cells, and in situ hybridization
analysis revealed that it is abundant in the choroid plexus, skeletal
muscle, osteoblasts of rib, and occipital bone in mouse embryos. Its
expression levels and transamidation efficiency decreased with
differentiation of embryonic stem cells. The 3T3 cell lines expressing
antisense mGPAA1 failed to express GPI-anchored proteins on
the cell surface membrane.
GPAA1; GAA1; glycosyl phosphatidylinositol; anchor; transamidase
