生命科学科研大百科

p70 S6 kinase is a mitogen‑activated Ser/Thr protein kinase essential for cell growth and G1 cell cycle progression. It phosphorylates the S6 protein of the 40S ribosomal subunit at key residues (Ser235, Ser236, Ser240, Ser244) and regulates translation of 5′ oligopyrimidine tract mRNAs. In vivo, it phosphorylates eIF4B at the rapamycin‑sensitive Ser422 site; the Ser422Ala mutant of eIF4B exhibits reduced activity in in vitro translation assays. Additionally, phosphorylation of eEF2K by p70 S6 kinase and p90RSK inactivates eEF2K, promoting eEF2 dephosphorylation and facilitating protein translation. This paper summarizes specific antibodies targeting key proteins in this pathway, providing experimental tools for related molecular mechanism studies.

The nucleosome, made up of four core histone proteins (H2A, H2B, H3, and H4), is the primary building block of chromatin. Originally thought to function as a static scaffold for DNA packaging, histones have now been shown to be dynamic proteins, undergoing multiple types of post-translational modifications, including acetylation, phosphorylation, methylation, and ubiquitination .

The p53 tumor suppressor protein is critical for cellular responses to DNA damage, triggering cell cycle arrest, DNA repair, or apoptosis. Its activity is tightly regulated via post‑translational modifications, including phosphorylation (Ser6/9/15/20/33/392) and acetylation (Lys382), which disrupt MDM2‑mediated degradation. Key kinases (ATM/ATR/Chk1/Chk2) and acetyltransferases (p300/CBP) modulate p53 function, while SIRT1 mediates deacetylation. Specific antibodies targeting modified p53 enable detection in research applications.

Organelle localization is a dynamic process regulated by the cytoskeleton and specific signal sequences. Endogenous targeting signals determine protein destinations, while exogenous strategies direct drugs and nanoparticles to organelles for therapy. Accurate subcellular distribution analysis aids therapeutic evaluation.

The NuRD complex is a key transcriptional repressor with nucleosome remodeling and histone deacetylase activities, comprising CHD3/4, HDAC1/2, RBAP46/48, MTA1-3, and MBD3. It regulates chromatin structure and gene expression, with specific antibodies available for research applications.

Nuclear receptors are ligand‑dependent transcription factors regulating reproduction, development and metabolism via post‑translational modifications. Key members include AR, ERα, GR, PPARγ, PR, RARs and RXRs, each mediating distinct biological processes. Relevant antibodies for research are listed.

Tight junctions (zona occludens) form a continuous fluid barrier across epithelium and endothelium, regulating paracellular permeability and maintaining cell polarity by blocking the movement of transmembrane proteins between apical and basolateral cell surfaces. Composed of claudin and occludin transmembrane proteins, tight junctions link to the cytoskeleton via zona occludens proteins ZO-1, ZO-2 and ZO-3. The claudin family determines epithelial barrier properties, while ZO-1 and ZO-2 are essential for tight junction assembly and function; ZO-3 negatively regulates junction formation. Afadin participates in cell movement directionality, and CD2AP contributes to tight junction formation in specialized cells and EGFR endocytosis. This paper also lists relevant antibodies for tight junction protein detection.

cLEF1 and TCF belong to the high mobility group (HMG) DNA‑binding transcription factor family, which includes LEF1, TCF1 (TCF7), TCF3 (TCF7L1), and TCF4 (TCF7L2). LEF1 and TCF1/TCF7 are key regulators of early lymphoid development and act downstream of the Wnt signaling pathway. They bind to Wnt response elements and provide docking sites for β‑catenin; upon Wnt activation, β‑catenin translocates into the nucleus to promote target gene transcription. These proteins are dynamically expressed during development, and aberrant activation of the Wnt pathway is associated with many cancers including colon cancer. Relevant antibodies for detecting these proteins and reference literature are also listed.

Neurofilaments, as the main intermediate filaments in neurons, play a vital role in maintaining neuronal structure and regulating axon growth and caliber. This paper systematically introduces the composition, structural characteristics and assembly mechanism of neurofilaments, and expounds the biological functions of related cytoskeletal proteins such as nestin, CNPase, GFAP, doublecortin, NeuN, MBP and Ki-67. A large number of studies have confirmed that neurofilament aggregation is closely related to the occurrence and development of various neurological diseases, and can be used as effective biomarkers for disease detection in cerebrospinal fluid and peripheral blood. In addition, this paper collates the corresponding antibody resources suitable for multiple experimental applications, providing a reference for related basic research and clinical transformation.

The innate immune system uses pattern recognition receptors (PRRs) that detect conserved pathogen-associated molecular patterns (PAMPs), such as cytoplasmic double-stranded RNA, to detect and initiate an immune response to viral infection. Detection of virus by PRRs leads to phosphorylation and nuclear translocation of IRF-3 and IRF-7, resulting in upregulation of type I interferons, which include IFN-α and IFN-β . Type I interferons signal through the interferon α/β receptor (IFNAR), leading to phosphorylation and activation of Stat1 and Stat2, which form a complex with IRF-9. This complex translocates to the nucleus where it induces transcription of interferon response genes including viral restriction factors, such as MX1, that limit viral replication and propagation .