All articles starting with P

Protein Flattop

Protein Flattop (CFAP126, C1orf192, Fltp; UniProt Q5VTH2) is a 177-aa human microtubule inner protein of ciliary doublet microtubules that regulates basal body docking, cilia positioning, and sperm motility.

Protein folding

Protein folding is the process by which a linear chain of amino acids acquires its functional three-dimensional native state; Anfinsen showed the sequence holds all needed information, and AlphaFold later predicted structures with high accuracy.

Protein footprinting

Protein footprinting is a solution-phase structural biology method that uses chemical or radical probes and mass spectrometry to map protein interaction surfaces, binding sites, and conformational change.

Protein FRG1

Protein FRG1 (FSHD region gene 1, UniProt Q14331) is a conserved 258-aa human 4q35 protein near the D4Z4 repeat; it binds RNA, copurifies with the spliceosome, bundles actin, and causes FSHD-like dystrophy when overexpressed in mouse muscle.

Protein fuseless

Fuseless (fusl, CG14021) is a Drosophila melanogaster gene encoding a 453-amino-acid, eight-pass transmembrane presynaptic protein that localizes Cacophony calcium channels to active zones; distinct from the fused kinase, fusilli, and fussel.

Protein GAPT

Protein GAPT (GRB2-binding adaptor protein, transmembrane) is a 157-aa B cell membrane adaptor identified in 2008 at Duke; it binds Grb2 constitutively via proline-rich motifs and negatively regulates BCR-driven B cell proliferation. Unrelated to the GAPT herbal formula.

Oct 20, 2026

Protein glutaminase

Protein glutaminase (protein-glutamine glutaminase, EC 3.5.1.44) is a deamidating enzyme from Chryseobacterium proteolyticum that converts protein-bound glutamine to glutamate, improving solubility, emulsification, and flavor of plant proteins; distinct from EC 3.5.1.2 glutaminase.

Protein heading date repressor 1

Protein heading date repressor 1 (HDR1, UniProt Q6K678) is a 210-amino-acid nuclear protein of rice that delays flowering under long days by upregulating Hd1, downregulating Ehd1, and reducing florigens Hd3a and RFT1, acting with the kinase OsK4.

Oct 20, 2026

Protein Her-1

Protein Her-1 (HER-1) is the secreted male sex-determination protein of C. elegans; it inhibits the TRA-2A receptor, has an all-helical structure, and acts cell non-autonomously.

Protein hinderin

Protein hinderin (KIAA1328) is a vertebrate coiled-coil protein that binds the SMC3 hinge and competes with SMC1, potentially modulating cohesin complex formation; located at human 18q12.2.

Oct 15, 2026

Protein Information Resource

The Protein Information Resource (PIR) is a public bioinformatics resource that collects and annotates protein sequence information, established in 1984 and a founding partner of UniProt since 2002.

Protein inhibitor of activated STAT

Protein inhibitor of activated STAT (PIAS): a family of four mammalian proteins (PIAS1, PIAS2/PIASx, PIAS3, PIAS4/PIASy) that inhibit STAT transcription factors' DNA binding and act as SUMO E3 ligases via SP-RING domains, also regulating NF-κB, p53, and p73 pathways.

Protein interaction mapping

Protein interaction mapping is the set of experimental methods, including yeast two-hybrid and affinity purification mass spectrometry, that identify physical interactions between proteins and assemble them into interaction networks.

Protein inturned

Protein inturned (INTU, UniProt Q9ULD6), a 942-aa CPLANE complex scaffold with a PDZ domain and three longin domains; forms a Rab23 GEF with Fuz, essential for ciliogenesis, Hedgehog signaling, and linked to skeletal ciliopathy.

Protein kinase A

Protein kinase A (PKA, cAMP-dependent protein kinase) is a tetrameric serine/threonine kinase; cAMP binding to regulatory subunits releases catalytic subunits that phosphorylate over 250 substrates, regulated by AKAP anchoring, discovered by Walsh and Krebs in 1968.

Protein kinase B gamma, catalytic domain

Catalytic kinase domain of AKT3 (PKBgamma, protein kinase B gamma), residues 148-405, an AGC-family serine/threonine kinase domain; gain-of-function mutations cause MPPH syndrome and hemimegalencephaly.

Protein kinase C

Protein kinase C (PKC), EC 2.7.11.13, is a family of 13 serine/threonine kinases in three classes, identified in 1982 as the receptor for tumor-promoting phorbol esters.

Protein kinase C, epsilon

Protein kinase C, epsilon (PKCε, PRKCE, EC 2.7.11.13) is a novel, calcium-independent, DAG-activated serine/threonine kinase involved in cardiac preconditioning, proliferation, oncogenesis, insulin signaling, pain, and alcohol consumption.

Protein kinase YpkA

Protein kinase YpkA, also called YopO in Yersinia enterocolitica, is an 80-kDa secreted serine/threonine kinase virulence factor of pathogenic Yersinia, activated by host actin and disrupting the cytoskeleton via a GDI-like domain.

Oct 20, 2026

Protein kish

Protein kish (KSH1, Ksh1p; protein kish-A, TMEM167A) is a small conserved eukaryotic membrane protein of about 8 kDa involved in the early secretory pathway, found in yeast, nematode, frog, and bird, defined by InterPro IPR009653 and Pfam PF06842.

Protein Kre1

Protein Kre1 (Kre1p, KRE1_YEAST, P17260) is a GPI-anchored Ser/Thr-rich cell-surface protein of Saccharomyces cerevisiae with a structural role in β-1,6-glucan assembly and as K1 killer toxin receptor.

Protein L2

Protein L2 (vaccinia virus L2R gene product) is an 87-amino-acid, 10-kDa ER-associated poxvirus membrane protein essential for crescent formation during virion morphogenesis; it stabilizes A30.5 and, indirectly, the entry-fusion complex.

Protein Lag2

Protein Lag2 names two unrelated proteins: C. elegans LAG-2, a DSL-family transmembrane Notch ligand for GLP-1/LIN-12 receptors, and yeast Lag2 (YOL025W, Q92325), the CAND1 homolog regulating SCF ubiquitin ligase rubylation and longevity.

Protein language model

A protein language model is a neural network, typically a Transformer, trained on large protein sequence databases to predict structure, function, and design in computational biology.

Protein ligation

Protein ligation is a set of chemical and enzymatic methods that join peptide or protein segments through a peptide bond, enabling synthesis of proteins with site-specific modifications such as noncoded amino acids.

Protein Lines

Protein Lines (Lines, LINS1, protein lines family): eukaryotic protein family defined by Pfam LINES_N (PF14694) and LINES_C (PF14695) domains; Drosophila lines is a nuclear Wnt/segment polarity regulator, human LINS1 (Q8NG48, 757 aa) is linked to autosomal recessive intellectual developmental disorder MRT27.