Sequences encoding the transcription start site, the start codon, the signal peptide, and the Gla module which is required for binding of the endogenous protein to phospholipid membranes were deleted. Normal transcript was undetected by Northern blot analysis of MEFs derived from homozygous mutant mice, while normal protein was shown to be absent from homozygous mutant kidney extracts by Western blot analysis using an antibody directed against the C-terminal.