High mobility group-like proteins of the insect Plodia interpunctella

Nuclei from Plodia interpunctella larvae contain four major proteins, which are extracted by 5% perchloric acid and 0.35 M NaCl. The proteins have been designated PL1, PL2, PL3, and PL4. The amino acid analyses of these proteins show that they have high proportions of acidic and basic amino acid residues, a property characteristic of the high mobility group (HMG) proteins isolated from vertebrate tissues. Immunological characterization of these proteins clearly shows that PL1, PL2, and PL4 are more closely related to HMG1 dipteran proteins, while PL3 is more closely related to HMGI dipteran proteins. The possible relatedness of these proteins to HMG proteins is discussed.