Seidler Contractile Proteins

Question 1

MyHC IIa gene and muscle fiber type?

Answer 1

MYH2

type 2A

Question 2

embryonic MyHC gene and muscle fiber type?

Answer 2

MYH3

fetal development, muscle regeneration

Question 3

Smooth Muscle MyHC gene and muscle fiber type?

Answer 3

MYH11

smooth m.

Question 4

fetal MyHC gene and muscle fiber type?

Answer 4

MYH8

fetal development, muscle regeneration

Question 5

Beta-cardiac MyHC gene and muscle fiber type?

Answer 5

MYH7

heart ventricles

Question 6

alpha-cardiac MyHC gene and muscle fiber type?

Answer 6

MYH6

heart atria

Question 7

Extraocular MyHC gene and muscle fiber type?

Answer 7

MYH13

extraocular muscle

Question 8

MyHC 1 gene and muscle fiber type?

Answer 8

MYH7

type 1

Question 9

mutation in what is associated with myosin storage myopathy?

what kind of myopathy?

Answer 9

MYH7

distal rod

Question 10

where does myosin self-assemble?

what chains make it up?

what can the head region do?

what is its rotational symmetry?

Answer 10

at the tails

2 heavy, 4 light

hydrolyze ATP

30 degrees

Question 11

how is actin arranged?

Answer 11

G-actin assembles into F-actin

Each G-actin binds 4 neighbors

Question 12

what binds free G-actin first?

Answer 12

ATP

Question 13

what does tropomodulin do?

Answer 13

caps the minus end, preventing further polymerization

Question 14

what does CapZ (b-actinin) do?

Answer 14

associates w/a-actinin

caps at the plus end

Question 15

what does Nebulin do?

Answer 15

ruler and template for actin polymerization

Question 16

what does Troponin T bind to?

function?

Answer 16

tropomyosin

positions the complex on the filament

Question 17

what does Troponin I bind to?

function?

Answer 17

actin

inhibits myosin binding

Question 18

what does Troponin C bind to?

function?

Answer 18

binds Ca2+

relieves inhibition

Question 19

what do costameres do?

Answer 19

tether Z disc to sarcolemma

Question 20

what is titin?

functions?

Answer 20

sarcomere ruler

passive elasticity
muscle signaling
balances forces across sarcomere

Question 21

what is diagnostic for a heart attack?

Answer 21

CK-MB

Question 22

describe the smooth m. contraction with Calcium and calmodulin

Answer 22

Calmodulin binds calcium, this binds the myosin light-chain kinase
kinase will phosphorylate the myosin light chain and myosin proteins get activated

Question 23

where is dystrophin located?

function?

Answer 23

costameres

tethers myofiber bundles to surface membranes and maintains the integrity of surface membrane during sheer stress of muscle contraction

Question 24

What is GSD V/McArdle disease?

Answer 24

deficiency in MUSCLE glycogen phosphorylase (RLS of glycogen degradation to release G1P)

Question 25

what are the Sx of McArdle disease?

Answer 25

m. cramping, myoglobinuria

it is allosterically activated by AMP

Question 26

What is Her’s disease?

how is it regulated?

Answer 26

GSD VI, mutation in LIVER glycogen phosphorylase

allosterically inhibited by ATP and G6P
inactivated by free glucose, NOT AMP

Question 27

what is sensitive to calcium?

Answer 27

muscle isozyme of phosphorylase

Question 28

defect in dystrophin results in what?

Answer 28

DMD, costamere disorganization, sarcolemma fragility, muscle weakness

Question 29

what is common with in-frame dystrophin mutations?

out-frame?

Answer 29

BMD

DMD

Question 30

what is found in cardiac muscle after a MI?

what is found in skeletal muscle?

Answer 30

cTn-1

sTn-1

Question 31

MyHC IIx/d gene and muscle fiber type?

Answer 31

MYH1

type 2b