PMID- 10361128 OWN - NLM STAT- MEDLINE DCOM- 19990701 LR - 20210216 IS - 0006-4971 (Print) IS - 0006-4971 (Linking) VI - 93 IP - 12 DP - 1999 Jun 15 TI - Factor XII Tenri, a novel cross-reacting material negative factor XII deficiency, occurs through a proteasome-mediated degradation. PG - 4300-8 AB - A homozygous cross-reacting material negative factor XII-deficient patient with 3% antigen and activity levels of factor XII was screened for the identification of a mutation at the genomic level. Low-ionic strength single-stranded conformation polymorphism (SSCP) analysis and sequence analysis showed that the proband's gene for factor XII had an A-->G substitution at nucleotide position 7832 in exon 3, resulting in a Tyr34 to Cys substitution in the NH2-terminal type II domain of factor XII. We designated this mutation as factor XII Tenri. Mutagenic polymerase chain reaction (PCR), followed by KpnI digestion, showed a homozygous mutation in the proband's gene and heterozygous mutations in his parents and sister. Immunoprecipitation and Western blot analyses of plasma samples from the factor XII Tenri family indicated that the proband had a trace amount of variant factor XII with an apparent molecular mass of 115 kD, which was converted to the normal 80-kD form after reduction, suggesting that factor XII Tenri was secreted as a disulfide-linked heterodimer with a approximately 35-kD protein, which we identified as alpha1-microglobulin by immunoblotting. Pulse-chase experiments using baby hamster kidney (BHK) cells showed that Tenri-type factor XII was extensively degraded intracellularly, but the addition of cystine resulted in increased secretion of the mutant. Using membrane-permeable inhibitors, we observed that the degradation occurred in the pre-Golgi, nonlysosomal compartment and a proteasome appeared to play a major role in this process. On the basis of these in vitro results, we speculate that the majority of the factor XII Tenri is degraded intracellularly through a quality control mechanism in the endoplasmic reticulum (ER), and a small amount of factor XII Tenri that formed a disulfide-linked heterodimer with alpha1-microglobulin is secreted into the blood stream. FAU - Kondo, S AU - Kondo S AD - Department of Life Science, Faculty of Science, Himeji Institute of Technology, Harima Science Garden City, Hyogo, Japan. FAU - Tokunaga, F AU - Tokunaga F FAU - Kawano, S AU - Kawano S FAU - Oono, Y AU - Oono Y FAU - Kumagai, S AU - Kumagai S FAU - Koide, T AU - Koide T LA - eng PT - Case Reports PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - United States TA - Blood JT - Blood JID - 7603509 RN - 0 (Glycoproteins) RN - 0 (Membrane Glycoproteins) RN - 0 (Multienzyme Complexes) RN - 0 (SPINT2 protein, human) RN - 9001-30-3 (Factor XII) RN - 9088-41-9 (Trypsin Inhibitor, Kunitz Soybean) RN - EC 3.1.21.4 (Deoxyribonucleases, Type II Site-Specific) RN - EC 3.1.21.4 (GGTACC-specific type II deoxyribonucleases) RN - EC 3.4.22.- (Cysteine Endopeptidases) RN - EC 3.4.25.1 (Proteasome Endopeptidase Complex) SB - IM MH - Adult MH - Base Sequence MH - Consanguinity MH - Cysteine Endopeptidases/*metabolism MH - DNA Mutational Analysis MH - Deoxyribonucleases, Type II Site-Specific/metabolism MH - Factor XII/*metabolism MH - Factor XII Deficiency/*genetics/metabolism MH - Glycoproteins/metabolism MH - Humans MH - Male MH - *Membrane Glycoproteins MH - Multienzyme Complexes/*metabolism MH - Mutagenesis, Site-Directed MH - *Mutation MH - Pedigree MH - Polymerase Chain Reaction MH - Polymorphism, Single-Stranded Conformational MH - Proteasome Endopeptidase Complex MH - Sequence Analysis, DNA MH - *Trypsin Inhibitor, Kunitz Soybean EDAT- 1999/06/11 00:00 MHDA- 1999/06/11 00:01 CRDT- 1999/06/11 00:00 PHST- 1999/06/11 00:00 [pubmed] PHST- 1999/06/11 00:01 [medline] PHST- 1999/06/11 00:00 [entrez] AID - S0006-4971(20)59460-3 [pii] PST - ppublish SO - Blood. 1999 Jun 15;93(12):4300-8.