TY - JOUR
T1 - Identification of a novel four-domain member of the proteinase inhibitor II family from the stigmas of Nicotiana alata
AU - Miller, Elizabeth A.
AU - Lee, Marcus C.S.
AU - Atkinson, Angela H.O.
AU - Anderson, Marilyn A.
N1 - Funding Information:
This work was supported by Australian Postgraduate Research Scholarships (to E.A.M. and M.C.S.L.) and by an Australian Research Council Post-Doctoral Fellowship (to A.H.O.A.).
PY - 2000/11
Y1 - 2000/11
N2 - Proteinase inhibitors (PIs) of the potato type II family have been identified in a number of solanaceous species. Most family members have two PI domains which are specific for either chymotrypsin or trypsin. More recently family members have been described with three or six repeated PI domains. Here we describe a novel four-domain family member produced in the stigmas and leaves of the ornamental tobacco, Nicotiana alata, which has high sequence identity with a six-domain member from the same species. Both proteins are produced as precursors that enter the secretory pathway and are subsequently processed into a series of 6 kDa PIs. The four- and six-domain precursor proteins were isolated from immature stigmas and characterised by mass spectrometry which revealed that both proteins had been trimmed at the N-terminus, at a position corresponding to the predicted signal peptide cleavage site. Furthermore, no post-translational modifications were apparent.
AB - Proteinase inhibitors (PIs) of the potato type II family have been identified in a number of solanaceous species. Most family members have two PI domains which are specific for either chymotrypsin or trypsin. More recently family members have been described with three or six repeated PI domains. Here we describe a novel four-domain family member produced in the stigmas and leaves of the ornamental tobacco, Nicotiana alata, which has high sequence identity with a six-domain member from the same species. Both proteins are produced as precursors that enter the secretory pathway and are subsequently processed into a series of 6 kDa PIs. The four- and six-domain precursor proteins were isolated from immature stigmas and characterised by mass spectrometry which revealed that both proteins had been trimmed at the N-terminus, at a position corresponding to the predicted signal peptide cleavage site. Furthermore, no post-translational modifications were apparent.
KW - Nicotiana alata
KW - Proteinase inhibitor II
KW - Stigma
UR - http://www.scopus.com/inward/record.url?scp=0034006114&partnerID=8YFLogxK
U2 - 10.1023/A:1006305429013
DO - 10.1023/A:1006305429013
M3 - Article
C2 - 10794532
AN - SCOPUS:0034006114
SN - 0167-4412
VL - 42
SP - 329
EP - 333
JO - Plant Molecular Biology
JF - Plant Molecular Biology
IS - 2
ER -