Term
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Definition
1. signal recognition particle (SRP) binds signal sequence on polypeptide
2. translation stalls/ SRP binds SRP receptor assoc. w/ translocon
3. GTP hydrolysis frees SRP and opens translocon
4. translation resumes, protein signal sequence cleaved inside membrane by signal peptidase
5. protein folds |
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Term
| unidirectional protein translation across membrane due to these proteins |
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Definition
Sec63 complex
Hsp70 BiP
Sec63 + ATP + BiP = ratcheting of protein thru membrane
BiP also maintains open PP chain until translation complete to facilitate proper folding |
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Term
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Definition
| single pass transmembrane protein inserted so that amino terminus faces lumen; signal sequence cleaved (Type III is the same except signal sequence not cleaved); peptide contain STOP TRANSFER ANCHOR SEQUENCE w/ hydrophobic residues that passes laterally through translocon to embed in membrane |
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Term
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Definition
| single pass transmembrane protein inserted so that amino terminus faces cytosol; signal sequence not cleaved; like Type III, contains SIGNAL ANCHOR SEQUENCE flanked by positively charged residues that locate on cytosolic face |
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Term
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Definition
| multi-pass transmembrane protein; odd number of passes = ends on opposite sides |
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Term
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Definition
| transmembrane proteins on extracellular side of membrane; protein inserted like Type I -> cleaved by GPI transamidase-> C' end attached to GPI anchor |
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Term
| protein processing that occurs only in ER |
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Definition
disulfide bond formation
proper folding/ multisubunit assembly |
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Term
| protein processing that occurs in the ER and Golgi |
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Definition
glycosylation
proteolytic cleavage |
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Term
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Definition
| first carbohydrate attaches to Ser or Thr w/ glycosyl transferases; ex: ABO blood groups |
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Term
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Definition
| attachment of preformed (on dolichol phosphate) carbohydrate structure to Asn of Asn-X-Ser/Thr by oligosaccharyl transferase (N = Asn) |
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Term
| formation of oligosaccharide precursor |
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Definition
| high mannose structure formed on dolichol phosphate starting in cytosol/ flips to ER lumen 1/2 way thru; 1st addition of MS by nucleotide sugar donor hydrolyzes UDP->UMP adding phosphate to base (2 total) |
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Term
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Definition
| antibiotic that blocks addition of first MS by UDP-sugar donor, preventing formation of high mannose glycosylation structure (UDP-N-acetylglucosamine analog) |
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Term
| signal that glycosylated protein is ready for ER -> Golgi transport? |
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Definition
| glycosylases remove 3 glucose and 1 specific mannose in ER lumen |
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Term
| what is the function of glycosylating proteins? |
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Definition
stabilizes protein (secreted proteins)
helps proper folding
cell-cell adhesion (ie CAMs) |
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Term
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Definition
| 2 cysteines bind via protein disulfide isomerase (PDI) in ER under oxidative conditions |
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Term
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Definition
| sugar-binding lectins that maintain unfolding state until proper folding can occur |
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Term
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Definition
| recycles PDI in disulfide bond formation process by oxidizing the molecule |
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Term
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Definition
| aka hyaluronan; D-glucuronic acid + N-acteylglucosamine in beta1-3 and beta 1-4 linkages; not a proteoglycan |
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Term
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Definition
| D-glucuronic acid + N-acteyl-D-galactosamine w/ beta1-3 and beta1-4 linkages |
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Term
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Definition
| L-iduronic acid + N-acetyl-D-galactosamine w/ alpha 1-3 and beta1-4 linkages |
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Term
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Definition
| galactose-6-sulfate + N-acetyl-D-glucosamine-6-sulfate w/ beta1-4 and beta1-3 linkages |
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Term
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Definition
| glucuronic acid or idouronic acid + N-acetylated or N-sulfated glucosamine w/ repeating alpha1-4 linkages |
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Term
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Definition
| MPS II; deficiency of iduronate sulfatase affecting "step 1" of DS and HS catabolism; treatment w/ Elaprase or Idusulfase |
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Term
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Definition
| MPS I; deficiency in alpha-L-iduronase affecting "step 2" of DS and HS catabolism; treatment w/ Aldurazyme or Laronidase |
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Term
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Definition
| MPS III; deficiency in heparan-N-sulfatase affecting "step 3" of HS catabolism |
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Term
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Definition
| MPS III; deficiency in acetyl-coa-acetyl-transferase affecting "step 4" of HS catabolism |
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Term
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Definition
| MPS III; deficiency in alpha-N-acetyl-glucosaminidase affecting "step 5" of HS catabolism |
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Term
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Definition
| MPS IV; deficiency in galactose-6-sulfatase affecting "step 1" of KS catabolism |
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Term
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Definition
| MPS IV; deficiency in beta-galactosidase affecting "step 2" of KS catabolism |
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Term
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Definition
| disaccharide repeat of N-acteylglucosamine + N-acteylmuramic acid in beta1-4 repeats |
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Term
| lysosomal acid hydrolases |
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Definition
function at pH range of 5-6
includes proteases, lipases, phosphatases, nucleases, glycosidases, |
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Term
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Definition
| invagination, brings fluids into cell |
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Term
| receptor-mediated endocytosis |
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Definition
| invagination, ligand binds to receptors in clathrin-coated pit on cell membrane and is then brought into cell inside vesicle |
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Term
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Definition
| after entry into cell with substrate, becomes acidified and enriched w/ lysosomal enzymes = lysosome |
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Term
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Definition
| evagination that engulfs particle, internalizes w/i a membrane (macrophages, neutrophils) |
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Term
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Definition
| phospholipid membrane surrounding cholesterol w/ apolipoprotein B (ligand for LDL receptor) |
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Term
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Definition
NPXY sorting signal
beta-propellor domain attached to binding arm (at low pH is + and binds to arm) |
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Term
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Definition
| iron + apotransferrin = ferrotransferrin -> binds to transferrin receptor and brought into cell-> at lower pH Fe dissociates -> apotransferrin and transferrin receptor leaves cell -> neutral pH causes apotransferrin to dissociate from transferrin receptor to find new Fe |
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Term
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Definition
| vesicle taken up by endosome through invagination, causing degradation of integral enzymes; ubiquinated Hrs proteins form ESCRT assembly to take in vesicles |
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Term
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Definition
| maintains unfolded protein for mitochondrial transport |
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Term
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Definition
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Term
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Definition
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Term
| targeting to mitochondrial matrix |
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Definition
| matrix targeting sequence -> binds to Tom, translocated thru Tom40 -> translocated thru Tim proteins -> sequence removed by proteases |
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Term
| targeting to inner mitochondrial membrane |
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Definition
Path A: hydrophobic stop sequence, moves laterally thru Tim pore (like Type I ER)
Path B: Oxa1 inner membrane protein + Oxa1 sequence in protein
Path C: multi-pass protein has multiple insertion sequences |
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Term
| targeting to mitochondrial intermembrane space |
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Definition
Path A: proteins have matrix and inner membrane targeting (hydrophobic) sequences -> protease cleaves domain in intermembrane space
Path B: only intermembrane targeting sequence; no Tim interaction |
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Term
| protein targeting to outer mitochondrial membrane |
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Definition
| protein has stop transfer and outer membrane sequences, goes thru Tom40 and SAM |
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Term
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Definition
nuclear encoded
uses O2
peroxisome targeting: PTS1 Ser-Lyc-Leu or SKL at C' |
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Term
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Definition
| pre-folded protein w/ PTS1 binds Pex5 in cytosol -> binds Pex receptor -> translocates thru Pex complex -> sequence not cleaved -> Pex 5 recycled |
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Term
| 3 important proteins involved in nuclear import |
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Definition
Ran (GTP-binding)
Importin-alpha (binds NLS)
Importin-beta (shuttles cargo) |
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Term
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Definition
| guanosine exchange factor that exchanges GDP for GTP |
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Term
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Definition
| GTPase activating protein- activates hydrolytic activity |
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Term
| Ran-independent mRNA nuclear export |
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Definition
| mRNP complex binds to Nxt1/TAP and nucleoporins -> mRNP remodeling + helicase activity of Dbp5 removes export complex -> Nxt1/TAP recycled via Ran-Importin mxn |
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Term
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Definition
actin binds ATP
networks
polarized
tracks for myosin
contraction/ cortex network |
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Term
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Definition
alpha-beta tubulin binds GTP
rigid
polarized
tracks for kinesin, dynein
organization, long-range transport of organelles |
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Term
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Definition
no nulceotide
tensile strength
unpolarized
no motors
cell, tissue integrity |
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Term
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Definition
mitotic spindle
interphase cellular structure
cellular transport
mvmt-cilia, flagella |
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Term
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Definition
| 13 protofilaments made of alpha- and beta-tubulin dimers |
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Term
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Definition
Tau
MAP2 (+ charged, assoc. w/ microtubules; phosphorylation destabilizes microtubules) |
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Term
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Definition
kinesin-13 family- binds + end dimers, monopolizes pool, promoting catastrophe
Op18/Stathmin- bends + end
Katanin- breaks microtubules exposing GDP caps |
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Term
| nucleation of microtubules |
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Definition
gamma-tubulin
pericentrin
forms gamma-TURC |
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Term
| centriole nucleating centers |
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Definition
pericentrin
gamma-tubulin
-form gamma-tubulin ring structure (gTuRC) |
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Term
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Definition
motor protein that moves - to +
ATP hydrolysis |
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Term
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Definition
motor proteins that move from + to -
ATP hydrolysis |
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Term
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Definition
stem-interacts w/ Dynactin (which binds cargo)
head-ATPase
stalk-microtubule binding site |
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Term
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Definition
| outer and inner arm dyneins form axonemal complex; move on doublet microtubules connected by Nexin protein |
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Term
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Definition
| function during mitosis to extend from/help orient spindle pole with respect to cell cortex/axis of cell division |
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Term
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Definition
attach to tips of chr.; function during mitosis to:
push duplicated chr. apart during prometaphase, help maintain spindle orientation, and push spindle poles apart during anaphase B |
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Term
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Definition
| function during mitosis to pull sister chromatids apart during anaphase A |
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Term
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Definition
| only one example given- KinC; occurs during spindle pole migration in order to align polar MTs |
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Term
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Definition
- end kinesin aligns polar MTs
+ end kinesin (BimC) pushes apart polar MT
- end dynein pulls astral MTs towards cortex |
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Term
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Definition
| kinesin in kinetochore that helps facilitate end capture of + end of kinetochore MT during mitosis |
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