Major component of the transverse central element of synaptonemal complexes (SCS), formed between homologous chromosomes during meiotic prophase (PubMed:36635604). Required for the assembly of the central element of the synaptonemal complex during meiosis, via remodeling of SYCP1 lattice structures and promoting recruitment of SYCE2-TEX12 and SYCE1-SIX60S1 complexes (PubMed:36635604). Required for chromosome loading of the central element-specific SCS proteins, and for initiating synapsis between homologous chromosomes (By similarity). Chromosome loading appears to require SYCP1 (By similarity). Required for fertility and normal testis development (By similarity). . This is the function of Ensembl gene identifier ENSG00000217442 (SYCE3, synaptonemal complex central element protein 3).