title: 42S p48--the most abundant protein in previtellogenic Xenopus oocytes--resembles elongation factor 1 alpha structurally and functionally.
abstract: We have undertaken an immunological and biochemical analysis of the most abundant soluble protein of previtellogenic Xenopus oocytes, 42S p48. We show that this protein shares immunological cross-reactivity with elongation factor 1 alpha (EF-1 alpha). Direct assays of both 42S fractions and purified 42S p48 show that this cross-reactivity is of functional significance since 42S p48, like EF-1 alpha, can transfer charged amino acids to ribosomes. We further demonstrate that 42S p48 is degraded soon after the onset of vitellogenesis, while the EF-1 alpha concentration remains essentially unchanged during this transition. These properties of 42S p48 are discussed with regard to its role in oogenesis.
mesh_terms: D000818:Animals; D003429:Cross Reactions; D004527:Egg Proteins / Q000276:immunology / Q000302:isolation & purification*; D000939:Epitopes / Q000032:analysis; D005260:Female; D009865:Oocytes / Q000032:analysis / Q000166:cytology*; D009866:Oogenesis; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000276:immunology / Q000302:isolation & purification*; D014819:Vitellogenins; D014982:Xenopus laevis
chemical_list: D004527:Egg Proteins; D000939:Epitopes; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D014819:Vitellogenins