La protein plays a role in the transcription of RNA polymerase III. It is most probably a transcription termination factor. Binds to the 3' termini of virtually all nascent polymerase III transcripts (By similarity). Barely detectable in stage I/II oocytes, accumulate in stage III/IV oocytes, then exhibit a roughly constant steady state level in mature oocytes, eggs, and early embryos. Phosphorylated. There are two forms of La, LaA and LaB, in Xenopus.