Amino acid sequence and domain structure of entactin. Homology with epidermal growth factor precursor and low density lipoprotein receptor.
Entactin (nidogen), a 150-kD sulfated glycoprotein, is a major component of basement membranes and forms a highly stable noncovalent complex with laminin. The complete amino acid sequence of mouse entactin has been derived from sequencing of cDNA clones. The 5.9-kb cDNA contains a 3,735-bp open reading frame followed by a 3'-untranslated region of 2.2 kb. The open reading frame encodes a 1,245-residue polypeptide with an unglycosylated Mr of 136,500, a 28-residue signal peptide, two Asn-linked glycosylation sites, and two potential Ca2+-binding sites. Analysis of the deduced amino acid sequence predicts that the molecule consists of two globular domains of 70 and 36 kD separated by a cysteine-rich domain of 28 kD. The COOH-terminal globular domain shows homology to the EGF precursor and the low density lipoprotein receptor. Entactin contains six EGF-type cysteine-rich repeat units and one copy of a cysteine-repeat motif found in thyroglobulin. The Arg-Gly-Asp cell recognition sequence is present in one of the EGF-type repeats, and a synthetic peptide from the putative cell-binding site of entactin was found to promote the attachment of mouse mammary tumor cells.
Durkin
M E
ME
Department of Biological Sciences, University of Pittsburgh, Pennsylvania 15260.
Chakravarti
S
S
Bartos
B B
BB
Liu
S H
SH
Friedman
R L
RL
Chung
A E
AE
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001485:Basement Membrane / Q000032:analysis*; D002448:Cell Adhesion; D002460:Cell Line; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004815:Epidermal Growth Factor / Q000235:genetics*; D006023:Glycoproteins / Q000032:analysis / Q000235:genetics*; D008562:Membrane Glycoproteins; D051379:Mice; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000235:genetics*; D011973:Receptors, LDL / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D006023:Glycoproteins; D008562:Membrane Glycoproteins; D011498:Protein Precursors; D011973:Receptors, LDL; C042652:epidermal growth factor precursor; C029967:nidogen; D004815:Epidermal Growth Factor; D004247:DNA