Kettering University

About: Kettering University is a education organization based out in Flint, Michigan, United States. It is known for research contribution in the topics: Cancer & RNA. The organization has 6842 authors who have published 7689 publications receiving 337503 citations. The organization is also known as: GMI Engineering & Management Institute & General Motors Institute.

Function in protein folding of TRiC, a cytosolic ring complex containing TCP-1 and structurally related subunits.

Abstract: T-complex polypeptide 1 (TCP-1) was analyzed as a potential chaperonin (GroEL/Hsp60) equivalent of the eukaryotic cytosol. We found TCP-1 to be part of a hetero-oligomeric 970 kDa complex containing several structurally related subunits of 52-65 kDa. These members of a new protein family are assembled into a TCP-1 ring complex (TRiC) which resembles the GroEL double ring. The main function of TRiC appears to be in chaperoning monomeric protein folding: TRiC binds unfolded polypeptides, thereby preventing their aggregation, and mediates the ATP-dependent renaturation of unfolded firefly luciferase and tubulin. At least in vitro, TRiC appears to function independently of a small co-chaperonin protein such as GroES. Folding of luciferase is mediated by TRiC but not by GroEL/ES. This suggests that the range of substrate proteins interacting productively with TRiC may differ from that of GroEL. We propose that TRiC mediates the folding of cytosolic proteins by a mechanism distinct from that of the chaperonins in specific aspects.

Properties of the K562 cell line, derived from a patient with chronic myeloid leukemia

Abstract: The K562 cell line derived from a CML patient in blast crisis was examined for properties of B and T lymphocytes and cell lines. K562 lacks the B markers of immunoglobulin, Epstein-Barr virus (EBV) genome and associated nuclear antigen, and receptors for EBV. A low proportion of cells form rosettes with sheep erythrocytes, the frequency of which is considerably increased after neuraminidase treatment. Unlike B lines but like T lines, K562 cells are lysed rapidly by C'/Fc receptor-positive human blood leukocytes and do not stimulate MLC reactions. On the other hand, K562 lacks T antigen, high radiosensitivity and sensitivity to growth inhibition by thymidine. The cells do not contain N-APase, an enzyme found in all lines derived from lymphoid cells and in lymphoproliferative diseases. By scanning electron microscopy, K562 cells were seen to be rounded and relatively smooth, with small numbers of short microvilli resembling undifferentiated leukemic cells. A few cells had narrow ridge-like profiles and small ruffles similar to granulocytic leukemic cells. K562 is strongly positive for immunoglobulin Fc receptors and pinocytosis, but does not phagocytose or mediate antibody-dependent phagocytosis or cytolysis. Among histochemical stains, K562 is positive for esterase, lipid, and acid phosphatase. There seems to be no doubt that K562 is not a B cell line. While it has some T cell properties, these are not exclusive. Some of its characteristics indicate that it is probably not lymphoid. Due to its low level of differentiation, its nature cannot be stated with certainty. On the basis of the possible presence of the cellular marker of chronic myeloid leukemia, the Ph chromosome, it may be regarded as belonging to the granulocytic series of cells. Propretes de la lignee k562, qui provient d'un sujet atteint de leucemie myeǐotde chronique La lignee K562, qui provient d'un sujet atteint de CML en crise blastique, a ete etudee du point de vue des proprietis des lymphocytes B et T et d'autres lignees cellulaires. Elk ne possede ni les marqueurs B de I'immunoglobuline, ni le genome du virus d'Epstein-Barr (EBV), ni l'antigene nucliaire qui h i est assocei, ni les recepteurs de I'EB V. Une faible proportion des cellules forment avec les erythrocytes de mouton des rosettes dont la frequence s'accrǐt considerablement aprds traitement a la neuraminidase. A la difkrence des lignees Bmais comme les ligntes T, les cellules K562 sont lysies rapidement par les leucocytes du sang humain portant des rkcepteurs C'IFc et ne stimulent pas les reactions en MLC. Par contre, elks nepossbdentpas l'antigbne Tet ne sont pas fortement radiosensibles; leur croissance n'est pas inhibke par la thymidine; elles ne contiennent pas de N-APase, une enzyme prisente dans toutes les lignies provenant de cellules lymphoides et dans les maladies Iymphoproliferatives. Au microscope eectronique ´ balayage, on constate que les cellules K562 sont arrondies, relativement lisses, avec quelques courtes microvillosites qui les font ressembler a des cellules leucemiques indifferenciees. Quelques cellules ont des protuberances en forme d'arětes etroites et de petites rides comme les cellules leucemiques granulocytaires. Pour les recepteurs Fc de l'immunoglobuline et la pinocytose, la lignee K562 est fortement positive. Elle ne phagocyte pas et ne declenche pas de phagocytose ou de cytolyse dependant de l'anticorps. Dans les tests de coloration histochimique, on a constate que la lignee K562 est positive pour l'esterase, les lipides et la phosphatase acide. Il ne s'agit incontestablement pas d'une lignee de cellules B. Si elle a quelques-unes des proprietes des cellules T, elle a aussi d'autres caracteristiques, dont certaines indiquent qu'elle n'est probablement pas lymphoide. Du fait de son faible niveau de differenciation, on ne peut pas determiner sa nature avec certitude. En raison de la presence possible du marqueur cellulaire de la leucemie myeloide chronique, le chromosome Ph, on peut considerer qu'elle appartient a la serie granulocytaire.

Killer Ig-Like Receptor Haplotype Analysis by Gene Content: Evidence for Genomic Diversity with a Minimum of Six Basic Framework Haplotypes, Each with Multiple Subsets

Abstract: Killer Ig-like receptor (KIR) genes constitute a multigene family whose genomic diversity is achieved through differences in gene content and allelic polymorphism. KIR haplotypes containing a single activating KIR gene (A-haplotypes), and KIR haplotypes with multiple activating receptor genes (B-haplotypes) have been described. We report the evaluation of KIR gene content in extended families, sibling pairs, and an unrelated Caucasian panel through identification of the presence or absence of 14 KIR genes and 2 pseudogenes. Haplotype definition included subtyping for the expressed and nonexpressed KIR2DL5 variants, for two alleles of pseudogene 3DP1, and for two alleles of 2DS4, including a novel 2DS4 allele, KIR1D. KIR1D appears functionally homologous to the rhesus monkey KIR1D and likely arose as a consequence of a 22 nucleotide deletion in the coding sequence of 2DS4, leading to disruption of Ig-domain 2D and a premature termination codon following the first amino acid in the putative transmembrane domain. Our investigations identified 11 haplotypes within 12 families. From 49 sibling pairs and 17 consanguineous DNA samples, an additional 12 haplotypes were predicted. Our studies support a model for KIR haplotype diversity based on six basic gene compositions. We suggest that the centromeric half of the KIR genomic region is comprised of three major combinations, while the telomeric half can assume a short form with either 2DS4 or KIR1D or a long form with multiple combinations of several stimulatory KIR genes. Additional rare haplotypes can be identified, and may have arisen by gene duplication, intergenic recombination, or deletions.