Recombinant Rat Centrosomal protein CEP57L1 (Cep57l1)

Primary Structure and Domains

Recombinant rat CEP57L1 is a 50.3 kDa protein comprising 430 amino acids . Its sequence includes:

• N-terminal PINC domain (amino acids 1–86): Facilitates centrosomal localization via interactions with pericentrin (PCNT) .

• Coiled-coil regions: Mediate homodimerization and heterodimerization with paralogs like Cep57 .

• Microtubule-binding motifs: Despite structural homology to Cep57, CEP57L1 lacks functional microtubule-binding activity .

Maintenance of Centriole Engagement

CEP57L1 and Cep57 form a redundant complex that prevents premature centriole disengagement during interphase. Codepletion of both proteins results in:

• Precocious centriole disengagement: 46.6% of cells exhibit separated centrioles in S/G2 phases .

• Centriole amplification: Disengaged centrioles acquire pericentriolar material (PCM) via Plk1-dependent pathways, leading to reduplication .

• Chromosomal instability: Amplified centrosomes cause multipolar spindles and segregation errors (22.1% of cells) .

Table 2: Phenotypic Consequences of CEP57L1/Cep57 Codepletion

Recombinant Expression Systems

Commercial vendors utilize multiple platforms for CEP57L1 production:

• Bacterial systems (E. coli): Yield 0.02 mg batches at $980.00 .

• Mammalian cells: Higher post-translational modification fidelity, used for structural studies .

• Baculovirus: Produces soluble protein for crystallography .

Mechanistic Studies of Centrosome Maturation

• Live-cell imaging: GFP-tagged CEP57L1 reveals dynamic centriole distancing during G2/M transition .

• STED microscopy: Resolves CEP57L1’s ring-like structure (111.1 nm radius) around mother centrioles .

• Co-immunoprecipitation: Validates interactions with Cep152 and Cep63, critical for centrosome assembly .

Disease Modeling

• Cancer research: Amplified centrosomes from CEP57L1 dysfunction correlate with aneuploidy in tumors .

• Polycystic kidney disease: Links to Pkd1/Pkhd1 mutations in rat models .

Antibodies and ELISA Kits

• CAB8290 (Assay Genie): Rabbit polyclonal antibody targeting residues 1–167; validated for WB/IF .

• Abbexa ELISA Kit: Detects CEP57L1 in rat tissues (sensitivity <0.07 ng/ml) .

Inhibitor Studies

Plk1 inhibitors (e.g., BI2536) suppress PCM recruitment to disengaged centrioles (13.1% vs. 51.6% in controls) .

Expression and Solubility

• Aggregation in mammalian systems: Addressed by co-expression with chaperones or solubility tags .

• Low yield in E. coli: Optimized via codon harmonization and induction at 18°C .

Functional Redundancy

CEP57L1’s overlap with Cep57 necessitates dual siRNA strategies for phenotypic studies .

Future Directions

• Structural biology: Cryo-EM of CEP57L1-PCNT complexes to map engagement interfaces.

• Chemical biology: High-throughput screens for small-molecule stabilizers of centriole engagement.