SCP2: a major protein component of the axial elements of synaptonemal complexes of the rat.
In the axial elements of synaptonemal complexes (SCs) of the rat, major protein components have been identified, with relative electrophoretic mobilities (M rs) of 30 000-33 000 and 190 000. Using monoclonal anti-SC antibodies, we isolated cDNA fragments which encode the 190 000 M r component of rat SCs. The translation product predicted from the nucleotide sequence of the cDNA, called SCP2 (for synaptonemal complex protein 2), is a basic protein (pI = 8.0) with a molecular mass of 173 kDa. At the C-terminus, a stretch of approximately 50 amino acid residues is predicted to be capable of forming coiled-coil structures. SCP2 contains two clusters of S/T-P motifs, which are common in DNA-binding proteins. These clusters flank the central, most basic part of the protein (pI = 9.5). Three of the S/T-P motifs are potential target sites for p34(cdc2) protein kinase. In addition, SCP2 has eight potential cAMP/cGMP-dependent protein kinase target sites. The gene encoding SCP2 is transcribed specifically in the testis, in meiotic prophase cells. At the amino acid sequence and secondary structural level, SCP2 shows some similarity to the Red1 protein, which is involved in meiotic recombination and the assembly of axial elements of SCs in yeast. We speculate that SCP2 is a DNA-binding protein involved in the structural organization of meiotic prophase chromosomes.
Offenberg
H H
HH
Department of Genetics, Agricultural University, Dreijenlaan 2, NL-6703 HA Wageningen, The Netherlands.
Schalk
J A
JA
Meuwissen
R L
RL
van Aalderen
M
M
Kester
H A
HA
Dietrich
A J
AJ
Heyting
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000302:isolation & purification; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008540:Meiosis; D051379:Mice; D008969:Molecular Sequence Data; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013573:Synaptonemal Complex; D014158:Transcription, Genetic
D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C113093:Sycp2 protein, rat