| Id |
Subject |
Object |
Predicate |
Lexical cue |
| T1 |
0-160 |
Sentence |
denotes |
Dimerization of cGMP-dependent protein kinase Ibeta is mediated by an extensive amino-terminal leucine zipper motif, and dimerization modulates enzyme function. |
| T2 |
161-225 |
Sentence |
denotes |
All mammalian cGMP-dependent protein kinases (PKGs) are dimeric. |
| T3 |
226-355 |
Sentence |
denotes |
Dimerization of PKGs involves sequences located near the amino termini, which contain a conserved, extended leucine zipper motif. |
| T4 |
356-565 |
Sentence |
denotes |
In PKG Ibeta this includes eight Leu/Ile heptad repeats, and in the present study, deletion and site-directed mutagenesis have been used to systematically delete these repeats or substitute individual Leu/Ile. |
| T5 |
566-668 |
Sentence |
denotes |
The enzymatic properties and quaternary structures of these purified PKG mutants have been determined. |
| T6 |
669-732 |
Sentence |
denotes |
All had specific enzyme activities comparable to wild type PKG. |
| T7 |
733-965 |
Sentence |
denotes |
Simultaneous substitution of alanine at four or more of the Leu/Ile heptad repeats ((L3A/L10A/L17A/I24A), (L31A/I38A/L45A/I52A), (L17A/I24A/L31A/I38A/L45A/I52A), and (L3A/L10A/L45A/I52A)) of the motif produces a monomeric PKG Ibeta. |
| T8 |
966-1088 |
Sentence |
denotes |
Mutation of two Leu/Ile heptad repeats can produce either a dimeric (L3A/L10A) or monomeric (L17A/I24A and L31A/I38A) PKG. |
| T9 |
1089-1169 |
Sentence |
denotes |
Point mutation of Leu-17 or Ile-24 (L17A or I24A) does not disrupt dimerization. |
| T10 |
1170-1272 |
Sentence |
denotes |
These results suggest that all eight Leu/Ile heptad repeats are involved in dimerization of PKG Ibeta. |
| T11 |
1273-1469 |
Sentence |
denotes |
Six of the eight repeats are sufficient to mediate dimerization, but substitutions at some positions (Leu-17, Ile-24, Leu-31, and Ile-38) appear to have greater impact than others on dimerization. |
| T12 |
1470-1799 |
Sentence |
denotes |
The Ka of cGMP for activation of monomeric mutants (PKG Ibeta (delta1-52) and PKG Ibeta L17A/I24A/L31A/I38A/L45A/I52A) is 2- to 3-fold greater than that for wild type dimeric PKG Ibeta, and there is a corresponding 2- to 3-fold increase in cGMP-dissociation rate of the high affinity cGMP-binding site (site A) of these monomers. |
| T13 |
1800-1897 |
Sentence |
denotes |
These results indicate that dimerization increases sensitivity for cGMP activation of the enzyme. |
