Open AccessThe 100‐kDa chain of nicein/kalinin is a laminin B2 chain variant
Author(s) -
VAILLY Joëlle,
VERRANDO Patrick,
CHAMPLIAUD MarieFrance,
GERECKE Donald,
WAGMAN D. Wolf,
BAUDOIN Christian,
ABERDAM Daniel,
BURGESON Robert,
BAUER Eugene,
ORTONNE JeanPaul
Publication year - 1994
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1994.tb19932.x
Subject(s) - laminin , complementary dna , protein subunit , basement membrane , microbiology and biotechnology , peptide sequence , biology , open reading frame , genetics , extracellular matrix , chemistry , gene
We have isolated the basement membrane component nicein and performed rotary‐shadow analyses using electron microscopy that showed the presence of two forms (I and II) of the protein. Molecular cloning of the cDNA that codes for the 100‐kDa chain of the protein revealed that the sequence matches those independently identified for the 105–155‐kDa subunit of kalinin, a recently identified basement membrane component. These data demonstrate that nicein and kalinin contain an identical chain. The length of the open reading frame in the cDNA (∼5200 nucleotides) and amino acid sequences obtained from the N‐terminus of the 105‐kDa kalinin chain showed the occurrence of a precursor polypeptide. This immature polypeptide is probably related to form I, observed by rotary shadowing, while the mature form is related to form II. It is noteworthy that nicein/kalinin subunits share‐discrete sequence similarities with the B2 chain of human laminin, but with a cleavage occurring within domain III that eliminates domains IV and V from the final product. The sequence of this subunit is nearly identical to that of B2t, a recently described polypeptide supposed to be related to a new laminin variant. Since nicein/kalinin expression is specifically impaired in the severe genodermatosis Herlitz junctional epidermolysis bullosa, the role and structure of this tissue‐restricted laminin variant is crucial for the understanding of epidermal‐dermal adhesion.