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KPNA2
Importin subunit alpha-1 is a protein that in humans is encoded by the ''KPNA2'' gene. The import of proteins into the nucleus is a process that involves at least 2 steps. The first is an energy-independent docking of the protein to the nuclear envelope and the second is an energy-dependent translocation through the nuclear pore complex. Imported proteins require a nuclear localization sequence (NLS) which generally consists of a short region of basic amino acids or 2 such regions spaced about 10 amino acids apart. Proteins involved in the first step of nuclear import are members of the alpha importin family of karyopherins such as importin subunit alpha-1. These include the ''Xenopus'' protein importin and its yeast homolog, SRP1 (a suppressor of certain temperature-sensitive mutations of RNA polymerase I in ''Saccharomyces cerevisiae''), which bind to the NLS. KPNA2 protein interacts with the NLSs of DNA helicase Q1 and SV40 T antigen and may be involved in the nuclear tran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITK (gene)
Tyrosine-protein kinase ITK/TSK also known as interleukin-2-inducible T-cell kinase or simply ITK, is a protein that in humans is encoded by the ''ITK'' gene. ITK is a member of the TEC (gene), TEC family of kinases and is highly expressed in T cells. Function This gene encodes an intracellular tyrosine kinase expressed in T-cells. The protein is thought to play a role in T-cell cell growth, proliferation and cellular differentiation, differentiation. ITK is functionally important for the development and effector function of T helper cell, Th2 and T helper 17 cell, Th17 cells. Mice lacking ITK were shown to not be susceptible to asthma. Structure This protein contains the following protein domain, domains, which are often found in intracellular kinases: * N-terminus – PH domain, PH (pleckstrin homology domain) * TH – Tec family homology domain (including Bruton's tyrosine kinase Cys-rich motif and Proline rich region) * SH3 domain, SH3 – (Src homology 3) * SH2 doma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Importin
Importin is a type of karyopherin that transports protein molecules from the cell's cytoplasm to the nucleus. It does so by binding to specific recognition sequences, called nuclear localization sequences (NLS). Importin has two subunits, importin α and importin β. Members of the importin-β family can bind and transport cargo by themselves, or can form heterodimers with importin-α. As part of a heterodimer, importin-β mediates interactions with the pore complex, while importin-α acts as an adaptor protein to bind the nuclear localization signal (NLS) on the cargo. The NLS-Importin α-Importin β trimer dissociates after binding to Ran GTP inside the nucleus, with the two importin proteins being recycled to the cytoplasm for further use. Discovery Importin can exist as either a heterodimer of importin-α/β or as a monomer of Importin-β. Importin-α was first isolated in 1994 by a group includinEnno Hartmann based at the Max Delbrück Center for Molecular Medicine. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyopherin
Karyopherins are proteins involved in transporting molecules between the cytoplasm and the nucleus of a eukaryotic cell. The inside of the nucleus is called the karyoplasm (or nucleoplasm). Generally, karyopherin-mediated transport occurs through nuclear pores which acts as a gateway into and out of the nucleus. Most proteins require karyopherins to traverse the nuclear pore. Karyopherins can act as ''importins'' (i.e. helping proteins get into the nucleus) or ''exportins'' (i.e. helping proteins get out of the nucleus). They belong to the nuclear pore complex family in the transporter classification database (TCDB). Energy for transport is derived from the Ran gradient. Upon stress, several karyopherins stop shuttling between the nucleus and the cytoplasm and are sequestered in stress granules, cytoplasmic aggregates of ribonucleoprotein complexes. Importin beta Importin beta is a variety of karyopherin that facilitates the transport of cargo proteins into the nucleus. Firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RNA Polymerase I
RNA polymerase 1 (also known as Pol I) is, in higher eukaryotes, the polymerase that only transcribes ribosomal RNA (but not 5S rRNA, which is synthesized by RNA polymerase III), a type of RNA that accounts for over 50% of the total RNA synthesized in a cell. Structure and function Pol I is a 590 kDa enzyme that consists of 14 protein subunits (polypeptides), and its crystal structure in the yeast ''Saccharomyces cerevisiae'' was solved at 2.8Å resolution in 2013. Twelve of its subunits have identical or related counterparts in RNA polymerase II (Pol II) and RNA polymerase III (Pol III). The other two subunits are related to Pol II initiation factors and have structural homologues in Pol III. Ribosomal DNA transcription is confined to the nucleolus, where about 400 copies of the 42.9-kb rDNA gene are present, arranged as tandem repeats in nucleolus organizer regions. Each copy contains a ~13.3 kb sequence encoding the 18S ribosomal RNA, 18S, the 5.8S, and the 28S RNA molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KPNB1
Importin subunit beta-1 is a protein that in humans is encoded by the ''KPNB1'' gene. Function Nucleocytoplasmic transport, a signal- and energy-dependent process, takes place through nuclear pore complexes embedded in the nuclear envelope. The import of proteins containing a classical nuclear localization signal (NLS) requires the NLS import receptor, a heterodimer of importin alpha and beta subunits. Each of these subunits are part of the karyopherin family of proteins. Importin alpha binds the NLS-containing cargo in the cytoplasm and importin beta docks the complex at the cytoplasmic side of the nuclear pore complex. In the presence of nucleoside triphosphates and the small GTP binding protein Ran, the complex moves into the nuclear pore complex and the importin subunits dissociate. Importin alpha enters the nucleoplasm with its passenger protein and importin beta remains at the pore. Interactions between importin beta and the FG repeats of nucleoporins are essential in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Immunology
''International Immunology'' is a peer-reviewed medical journal published by Oxford University Press on behalf of the Japanese Society for Immunology, addressing studies in allergology and immunology. Abstracting and indexing ''International Immunology'' is abstracted and indexed in Science Citation Index, Current Contents/Life Sciences, MEDLINE/Index Medicus, EMBASE, and BIOSIS Previews. According to the ''Journal Citation Reports'', its 2009 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... is 3.403, ranking it 41 out of 128 journals in the category "Immunology". External links * {{Official website, http://intimm.oupjournals.org/ Japanese Society for Immunology English-language journals Publications established in 1989 Immunology journals Monthly journals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARL4A
ADP-ribosylation factor-like protein 4A is a protein that in humans is encoded by the ''ARL4A'' gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b .... Function ADP-ribosylation factor-like 4A is a member of the ADP-ribosylation factor family of GTP-binding proteins. ARL4A is similar to ARL4C and ARL4D and each has a nuclear localization signal and an unusually high guanine nucleotide exchange rate. ARL4A is located in both the nuclear and extranuclear cell compartments. Multiple transcript variants encoding the same protein have been found for this gene. Interactions ARL4A has been shown to interact with Karyopherin alpha 2. References Further reading * * * * External links * * {{gene-7-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V(D)J Recombination
V(D)J recombination is the mechanism of somatic recombination that occurs only in developing lymphocytes during the early stages of T and B cell maturation. It results in the highly diverse repertoire of antibodies/immunoglobulins and T cell receptors (TCRs) found in B cells and T cells, respectively. The process is a defining feature of the adaptive immune system. V(D)J recombination in mammals occurs in the primary lymphoid organs ( bone marrow for B cells and thymus for T cells) and in a nearly random fashion rearranges variable (V), joining (J), and in some cases, diversity (D) gene segments. The process ultimately results in novel amino acid sequences in the antigen-binding regions of immunoglobulins and TCRs that allow for the recognition of antigens from nearly all pathogens including bacteria, viruses, parasites, and worms as well as "altered self cells" as seen in cancer. The recognition can also be allergic in nature (''e.g.'' to pollen or other allergens) or may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SV40 Large T-antigen
SV40 large T antigen ( Simian Vacuolating Virus 40 TAg) is a hexamer protein that is a dominant-acting oncoprotein derived from the polyomavirus SV40. TAg is capable of inducing malignant transformation of a variety of cell types. The transforming activity of TAg is due in large part to its perturbation of the retinoblastoma ( pRb) and p53 tumor suppressor proteins. In addition, TAg binds to several other cellular factors, including the transcriptional co-activators p300 and CBP, which may contribute to its transformation function. TAg is a product of an early gene transcribed during viral infection by SV40, and is involved in viral genome replication and regulation of host cell cycle. SV40 is a double-stranded, circular DNA virus belonging to the Polyomaviridae (earlier Papovavirus) family, Orthopolyomavirus genus. Polyomaviruses infect a wide variety of vertebrates and cause solid tumours at multiple sites. SV40 was isolated by Sweet and Maurice Hilleman in 1960 in prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RECQL
ATP-dependent DNA helicase Q1 is an enzyme that in humans is encoded by the ''RECQL'' gene. The protein encoded by this gene is a member of the RecQ DNA helicase family. DNA helicases are enzymes involved in various types of DNA repair, including mismatch repair, nucleotide excision repair and direct repair. Some members of this family are associated with genetic disorders with predisposition to malignancy and chromosomal instability. The biological function of this helicase has not yet been determined. Two alternatively spliced transcripts, which encode the same isoform but differ in their 5' and 3' UTRs, have been described. Interactions RECQL has been shown to interact with KPNA4 Importin subunit alpha-3, also known as karyopherin subunit alpha-4, is a protein that in humans is encoded by the ''KPNA4'' gene. Function The nuclear import of karyophilic proteins is directed by short amino acid sequences termed nuclear loca ... and Karyopherin alpha 2. References Further re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
