Protein Import and Modification

<p>GPI anchors attach proteins to the membrane, orienting them toward the extracellular environment. (D)</p> Signup and view all the answers

<p>Disulfide bonds covalently link amino acid residues, stabilizing protein structure, especially in extracellular conditions. (B)</p> Signup and view all the answers

<p>N-glycosylation aids in protein folding and function by attaching sugars to asparagine residues. (B)</p> Signup and view all the answers

<p>Protein disulfide isomerase (PDI) (D)</p> Signup and view all the answers

<p>It supports various biochemical reactions, emphasizing the specialized environment needed for precise protein processing and maturation. (A)</p> Signup and view all the answers

<p>To provide the energy required for building macromolecules through the breaking of covalent bonds. (D)</p> Signup and view all the answers

<p>Vesicles are membrane-bound carriers without internal reactions, whereas organelles are compartments where specific reactions occur. (C)</p> Signup and view all the answers

<p>It allows for the real-time observation of molecular interactions and events occurring within milliseconds, capturing dynamic processes. (C)</p> Signup and view all the answers

<p>It provides the framework for the directed movement of vesicles to precise cellular locations. (B)</p> Signup and view all the answers

<p>They maintain cell shape and enable the compartmentalization of vesicles and organelles. (C)</p> Signup and view all the answers

<p>Smooth Endoplasmic Reticulum (B)</p> Signup and view all the answers

<p>It enables precise vesicular exchange and material movement through specific chemical interactions. (A)</p> Signup and view all the answers

<p>They are based on observations of cells fixed onto slides, which do not capture the real-time dynamics of cellular processes. (B)</p> Signup and view all the answers

<p>By recognizing and interacting with specific effector proteins, facilitating the recruitment of SNARE proteins. (A)</p> Signup and view all the answers

<p>GEFs facilitate the exchange of GDP for GTP on Rab proteins, activating them. (A)</p> Signup and view all the answers

<p>mRNA (D)</p> Signup and view all the answers

<p>It promotes the activity of a kinase that phosphorylates phosphatidylinositol, generating PIP3. (D)</p> Signup and view all the answers

<p>They facilitate the transport of vesicles along the cytoskeletal network toward their target membranes. (B)</p> Signup and view all the answers

<p>Rab5 is primarily localized to early endosomes, while Rab7 is associated with late endosomes. (B)</p> Signup and view all the answers

<p>Decreased activation of the Rab protein, disrupting its specific membrane trafficking pathway. (B)</p> Signup and view all the answers

<p>Rab proteins recruit specific vSNARE and tSNARE pairs, ensuring that only the correct membranes fuse. (D)</p> Signup and view all the answers

<p>To create dynamic regions where essential proteins are organized and concentrated. (B)</p> Signup and view all the answers

<p>They form the 'identity coat' of membranes, enabling membrane fusion and defining cellular functions. (D)</p> Signup and view all the answers

<p>Ran GDP would accumulate in the nucleus, impairing nuclear export. (B)</p> Signup and view all the answers

<p>NFAT would be continuously dephosphorylated and translocated to the nucleus, leading to unregulated gene transcription. (B)</p> Signup and view all the answers

<p>Shift from Rab5 identity to Rab7 identity, along with changes in phosphoinositide composition. (C)</p> Signup and view all the answers

<p>It signals the endosome's progression toward becoming a late endosome or lysosome. (B)</p> Signup and view all the answers

<p>Ran GTP levels in the cytosol would significantly increase, disrupting the Ran GTP/GDP gradient and impairing both import and export. (D)</p> Signup and view all the answers

<p>NFAT would remain phosphorylated, unable to translocate to the nucleus and activate gene transcription. (A)</p> Signup and view all the answers

<p>The activation of GEFs (guanine nucleotide exchange factors) specific to Rab7 and inactivation of Rab5. (A)</p> Signup and view all the answers

<p>They recruit specific effector proteins that define the membrane's function and interaction capabilities. (C)</p> Signup and view all the answers

<p>Nuclear pores enable the selective compartmentalization of proteins, maintaining them in an inactive state in the cytosol until needed in the nucleus. (B)</p> Signup and view all the answers

<p>Ran GEF's nuclear localization and RanGAP's cytosolic localization establish a Ran GTP gradient, promoting import and export. (A)</p> Signup and view all the answers

<p>The plasma membrane (C)</p> Signup and view all the answers

<p>Maturation requires specific regulatory mechanisms that alter the molecular composition of the membrane, whereas initial fusion is a more general process. (B)</p> Signup and view all the answers

<p>NFAT phosphorylation levels would be increased, preventing its nuclear translocation despite calcineurin activity. (D)</p> Signup and view all the answers

<p>The mutation could impair the controlled entry of transcription factors into the nucleus causing aberrant gene expression patterns. (B)</p> Signup and view all the answers

<p>They can be transported to lysosomes via exocytosis or delivered to the plasma membrane through regulated or unregulated pathways. (D)</p> Signup and view all the answers

<p>Endo H sensitivity suggests the protein retains a high concentration of mannose and has not yet fully matured within the Golgi. (D)</p> Signup and view all the answers

<p>The protein lacks the necessary signals for proper trafficking and modifications within the Golgi. (D)</p> Signup and view all the answers

<p>They function as ligands for various receptors, facilitating important interactions that influence cellular communication and function. (D)</p> Signup and view all the answers

<p>Lysosomal enzymes will not be properly targeted, leading to their secretion instead of delivery to lysosomes. (D)</p> Signup and view all the answers

<p>Addition of glucose residues in the ER → sequential removal of glucose residues → addition of mannose residues → removal of mannose residues and addition of GlcNAc in the Golgi. (C)</p> Signup and view all the answers

<p>A mutation that prevents the addition of mannose-6-phosphate (M6P) residues. (B)</p> Signup and view all the answers

<p>Lysosomal enzymes would be mis-targeted and secreted extracellularly, leading to reduced intracellular degradation. (A)</p> Signup and view all the answers

Molecules that carry and release energy through covalent bond breaking (e.g., ATP, NAD).

Transport of materials via vesicles, involving specific interactions between organelles.

Organelles are compartments for reactions; vesicles are membrane-bound carriers without reactions.

Regulates directed movement of vesicles in cellular trafficking.

Cell membranes are made of phospholipids, lipids, and cholesterol, crucial for cell structure.

Technique to observe cellular processes in real-time for accurate understanding of dynamics.

Separation within organelles allowing specific reactions to occur efficiently.

Maintains cell shape and enables vesicle and organelle compartmentalization.

The state in which a protein remains flexible during import, allowing it to traverse membranes.

Molecules that help keep proteins unfolded or assist in their proper folding during transport.

A process that requires ATP energy for the active transport of proteins.

A cellular compartment where biochemical modifications essential for protein maturation occur.

Modifiers that attach an amphipathic lipid to proteins for their membrane embedding.

Covalent bonds formed between cysteine residues to stabilize protein structures.

The process of adding sugars to proteins, crucial for their folding and function.

A specific type of glycosylation where sugars attach to asparagine residues in proteins.

The process of exchanging GDP for GTP to activate GTPases.

Proteins that facilitate the exchange of GDP for GTP in GTPases.

The active form of the Ran protein, bound to GTP, facilitating nuclear transport.

Structures that regulate the transport of molecules in and out of the nucleus.

The activation of calcineurin by calcium, leading to dephosphorylation of substrates.

A transcription factor activated by calcineurin, regulating gene transcription.

The process of adding phosphate groups, keeping NFAT-C4 inactive in the cytosol.

Proteins and RNA transported through nuclear pores, facilitated by Ran GTP.

Small regions that organize essential proteins in signaling processes.

The specific characteristics of a membrane defined by its protein and lipid composition.

Lipids that play crucial roles in cell signaling and membrane identity.

Proteins essential for the fusion of vesicles with target membranes.

Proteins that regulate vesicle transport and membrane identity transitions.

Vesicles formed by endocytosis that begin the sorting process of proteins.

The process where early endosomes lose Rab5 identity and gain Rab7 as they mature.

The specific mix of phosphoinositides that characterize membranes at different maturation stages.

GTP interacts with GEF at the nuclear lamina, aiding nuclear signaling.

Small GTPases that control membrane fusion and vesicle identity.

A group including Rab proteins, crucial for cellular functions.

Transport process of vesicles guided by Rab proteins and SNAREs.

Types of SNAREs that help in vesicle and target membrane fusion.

Proteins that transport vesicles along the cytoskeleton for targeting.

Organelle responsible for processing and modifying proteins post-ER.

Presence of many mannose residues on glycoproteins exiting the ER.

Enzyme that distinguishes glycosylation states by sensitivity to mannose.

Indicates a protein retains high mannose and is not fully processed.

Indicates a protein has fewer mannose residues and is mature.

Proteins with carbohydrate chains, crucial for cell signaling and interaction.

Process by which glycosylated proteins facilitate communication between cells.