L63, the Drosophila PFTAIRE, interacts with two novel proteins unrelated to cyclins

Mech Dev. 2003 May;120(5):617-28. doi: 10.1016/s0925-4773(03)00019-4.


L63 encodes a CDK-like protein homologous to the mammalian PFTAIRE. We showed previously that L63 provides a CDK-related function critical to development (Dev. Biol. 221 (2000) 23). We present here the first biochemical characterization of L63 kinase. In addition, we describe two novel Drosophila proteins, PIF-1 and PIF-2 (for PFTAIRE Interacting Factor-1 and -2), identified in a two-hybrid screen for their ability to interact with the amino-terminal region of L63. The full-length PIF-1 cDNA shows an unusual dicistronic organization. PIF-1A and PIF-1B (the L63 interactor) predicted proteins are expressed in vivo, and show a distinct expression profile during development. Interaction between L63 and PIF-1B was confirmed in vitro and in vivo. The role of this interaction remains to be demonstrated, but our data suggest that PIF-1B might serve as a regulator of L63.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • Blotting, Western
  • Cloning, Molecular
  • Cyclin-Dependent Kinases / genetics
  • Cyclin-Dependent Kinases / metabolism
  • Cyclin-Dependent Kinases / physiology*
  • Cysteine / chemistry
  • DNA, Complementary / metabolism
  • Drosophila
  • Drosophila Proteins / genetics
  • Drosophila Proteins / physiology*
  • Exons
  • Gene Expression Regulation, Developmental
  • Humans
  • Models, Genetic
  • Molecular Sequence Data
  • Precipitin Tests
  • Protein Binding
  • Protein Biosynthesis
  • Protein Isoforms
  • Protein Structure, Tertiary
  • RNA, Messenger / metabolism
  • Transcription, Genetic
  • Two-Hybrid System Techniques


  • DNA, Complementary
  • Drosophila Proteins
  • Protein Isoforms
  • RNA, Messenger
  • Cyclin-Dependent Kinases
  • Eip63E protein, Drosophila
  • Cysteine