A complementary DNA for glucokinase (GK) was cloned from mouse liver total RNA by a combination of the polymerase chain reaction (PCR) and mouse liver cDNA library screening. Liver- and {beta}-cell-specific exons 1 were isolated by PCR using mouse and rat genomic DNAs. These clones were then used to screen a mouse genomic library; three genomic clones were isolated and characterized. The mouse GK gene spans over 20 kb, containing 11 exons including a liver- or {beta}-cell-specific exon 1, which encodes a tissue-specific 15-aa peptide at the N-terminus of the protein. Both types of GK contain 465 amino acid residues. The predicted amino acid sequence of mouse {beta}-cell-specific GK showed 98 and 96% identity to the rat and human enzymes, respectively; the corresponding values are 98 and 95% respectively, for the liver-specific GK. Several transcription factor-binding consensus sequences are identified in the 5{prime} flanking region of the mouse GK gene. 21 refs., 1 fig.
