cDNA coding for the tail region of the high molecular weight rabbit neurofilament protein NF-H

A cDNA library was prepared from rabbit brain mRNA, in the expression vector, lambda gt11. The library was screened with polyclonal antibodies raised against the neurofilament protein NF-H, and a cloned cDNA (KMRH-1) was selected and characterized. The fusion protein coded for by KMRH-1 includes epitopes for two monoclonal antibodies which react with nonphosphorylated sites in the tail region of NF-H. The selected cDNA includes 891 base pairs. It hybridizes to human genomic DNA, as well as to rabbit genomic DNA, and to a rabbit brain mRNA with a size of 4.7 kilobases (kb). The sequence of KMRH-1 includes extensive repeating regions, including one duplicated 60-base segment. Within the first 196 bases, one 13-base segment is repeated 9 times. The cDNA codes for the carboxy-terminal 184 amino acid residues of NF-H, including a series of 9 serines, each surrounded by a similar group of amino acids: ..Ala.Lys.Ser.Pro.(Glu./Val.).Lys.. Comparison of the derived amino acid sequence for KMRH-1 indicates considerable divergence from the sequence information available for rodent NF-H (Robinson et al.: FEBS Lett 209:203-205, 1986). This diversity in amino acid sequence may account for the failure to induce tangles of neurofilaments in animals, such as rats, following treatment with doses of aluminum which are sufficient to induce such tangles in rabbits and to bring on seizures and behavioral pathology in both species.