Elevated 32-kDa LBP and low laminin mRNA expression in developing mouse cerebrum.
Several laminin receptors have been identified, originally a high-affinity 67-kDa laminin binding protein ('LBP-67'), and later galactosyltransferase and the low-affinity but functionally potent integrin receptors. Attempts at obtaining cDNA for LBP-67, although unsuccessful, have given rise to a full-length cDNA coding for an interesting 32-kDa protein, tentatively referred to as '32-kDa LBP', whose relationship to LBP-67 is unclear. Since no information is available on the in vivo expression of 32-kDa LBP mRNA nor of the three laminin chains during CNS development, appropriate 35S-antisense and -sense RNA probes were applied to developing mouse cerebral wall at embryonic day (E)10-16, birth and 1-3 weeks after birth. Expression was examined using Northern blot analysis and in situ hybridization. The 32-kDa LBP mRNA was found to be elevated during the embryonic and perinatal period, and then rapidly declined. At the cellular level, 32-kDa LBP mRNA was distributed throughout the embryonic cerebral wall and became concentrated during the perinatal period in the proliferative ventricular zone and in the cortical plate. By comparison, laminin B1, B2, and A chain mRNA expression was relatively low at all times examined, in keeping with the punctate distribution of laminin antigenicity previously observed by others in developing brain parenchyma. Whereas the functional characterization of 32-kDa LBP and the nature of its laminin and proposed nonlaminin ligands is incomplete, the elevated and unique distribution of 32-kDa LBP mRNA raises interesting questions of the role of 32-kDa LBP mRNA in CNS development.
Laurie
G W
GW
Department of Anatomy and Cell Biology, University of Virginia, Charlottesville 22908.
Stone
C M
CM
Yamada
Y
Y
D000375:Aging / Q000378:metabolism; D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism*; D015870:Gene Expression; D007797:Laminin / Q000096:biosynthesis*; D051379:Mice; D008810:Mice, Inbred C57BL / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D015347:RNA Probes; D012333:RNA, Messenger / Q000032:analysis; D011946:Receptors, Antigen / Q000096:biosynthesis*; D011971:Receptors, Immunologic / Q000096:biosynthesis*; D017474:Receptors, Laminin
D007797:Laminin; D015347:RNA Probes; D012333:RNA, Messenger; D011946:Receptors, Antigen; D011971:Receptors, Immunologic; D017474:Receptors, Laminin