ISOLATION, IDENTIFICATION, CHARACTERIZATION AND STABILITY OF NEW CYTOPLASMIC RNPS FROM VICIA-FABA SEEDS

A new small cytoplasmic ribonucleoprotein complex (scRNPs) was isolate d for the first time and its proteins and RNAs were identified. The re sults are summarised as follows: (1) Vicia faba seeds soaked for 20 h has four complexes between the RNA and the proteins, three of them are major (complexes 1, 2 and 3 or C1, C2 and C3) and one minor (C4). (2) Each complex contains two major proteins: complex 1 (C1) has 62 and 4 8 kDa patterns; C2 has 48 and 36 kDa; C3 has 36 and 25 kDa and C4 has 25 and 23 kDa. (3) The differences between the highest molecular weigh t major proteins of each complex are approximately 12 +/- 1 kDa (C1 ha s 62 kDa, C2 has 48 kDa, C3 has 36 kDa and the complex has 25 kDa). (4 ) Each of the three major complexes contain the same species of uridin e rich RNA which was characterised as U1, U4, U5 and U6, in addition t o the proteins mentioned above. (5) The RNA in the complexes was found to be from the type of uridine-rich small ribonucleic acids that bind with proteins. They are called small ribonucleoproteins (snRNPs), and because they are found for the first time in cytoplasm and not extrac ted from the nucleus as in the literature, the name small cytoplasmic ribonucleoproteins (scRNPs) is suggested. (6) The complexes were separ ated by a known method. (7) The complexes were also separated using a new technique of separation. (8) The RNA-protein complexes (scRNPs) we re found to be strongly stable in guanidine-HC1 (6 M), cyanobromide an d sodium dodecyl sulphate (10%) at 100 degrees C for 10 min. The compl exes were slightly affected by proteinase K degrading enzyme and stron gly stable with RNasel, which hydrolyses the ribonucleic acids. (9) Th e results reveal that the proteins in the complexes have a specific fu nction or enzymatic effect. Also, the uridine-rich RNAs (snRNA) U1, U4 , U5 and U6 which are the same scRNA were found to have an important r ole in the splicing of the pre-mRNA to give mRNA.