Differentiation-dependent expression of laminin-8 (alpha 4 beta 1 gamma 1) mRNAs in mouse 3T3-L1 adipocytes.
We report that laminin-8 (alpha 4 beta 1 gamma 1) is the specific isoform of laminin synthesized in adipocytes. Reverse transcription-polymerase chain reaction (RT-PCR) of mRNA from mouse 3T3-L1 cells with paired primers for alpha 1, alpha 2, alpha 3, alpha 4, alpha 5, beta 1, beta 2, beta 3, gamma 1 and gamma 2 laminins yielded amplified fragments only for alpha 4, beta 1 and gamma 1. A polyclonal antibody against mouse laminin-1 (alpha 1 beta 1 gamma 1) precipitated alpha 4 in addition to beta 1 and gamma 1, while the antibody against a deduced peptide sequence of mouse alpha 4 in addition to beta 1 and gamma 1 in addition to alpha 4. Thus, laminin-8 (alpha 4 beta 1 gamma 1) is the only isoform expressed in 3T3-L1 cells. Northern blots showed that the levels of alpha 4, beta 1 and gamma 1 mRNAs increased 2.5-fold during adipose conversion of 3T3-L1 cells. A 1062 bp cDNA fragment cloned by RT-PCR demonstrated a polymorphism in the mouse alpha 4 gene which would lead to five amino acid changes in the domain G.
Niimi
T
T
Graduate Program for Biochemical Regulation, Graduate School of Agricultural Sciences, Nagoya University, Japan.
Kumagai
C
C
Okano
M
M
Kitagawa
Y
Y
D016475:3T3 Cells; D017667:Adipocytes / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental; D007797:Laminin / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000032:analysis; D014158:Transcription, Genetic
D007797:Laminin; D012333:RNA, Messenger; C110308:laminin 8