Figure 1.

Expression of TGase1 in wild-type strains (YF29 and KACO) and mutant strains (KALE, TAYA, and LEMA). (A) Northern blots hybridized with a TGase1-specific cDNA probe (Upper) and with an oligonucleotide probe specific for 28S rRNA (Lower). Positions of RNA molecular weight markers are shown on the right (Upper). The autoradiograph is overexposed to demonstrate clearly the absence of TGase1 mRNA in KALE and TAYA. (B) Western blot probed with a rabbit polyclonal antibody raised against a C-terminal peptide of TGase1. Arrow indicates the position of the 92-kDa TGase1. A protein extract prepared from 3T3-J2 cells was included as a negative control. Neither KALE nor TAYA produced an enzyme band but a faint band is present in extract of LEMA cells, which contain a missense mutation.